Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lactoferrin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 937 records · Page 52Linked to original sources
PubMed2002

[Do lactoferrin, lysozyme and the lactoperoxidase-thiocyanate-hydrogen peroxide-system cause negative microbiological results in mastitis secretions?].

Lactoferrin, lysozyme and the lactoperoxidase-thiocyanate-peroxide-system are naturally occurring antimicrobial components of milk. The objective of this study was to examine, whether these components were responsible for negative results, when mastitis milk is cultured microbiologically. Quarter milk samples from 75 cows with clinical mastitis on a dairy farm in Brandenburg were submitted for microbiological culture and analysed for the content and the activities of the three components. Animals from all stages of lactation with clinical mastitis were included in the study. Animals were examined clinically and milk samples were collected prior to first treatment. Secretions from quarters with clinical mastitis were compared to those of neighbouring quarters without clinical mastitis. Secretions with positive cultural results were compared to those with negative results. The concentrations or activities of the three factors were significantly higher in the diseased quarters than in the quarters without clinical signs of mastitis. The concentration of lysozyme increased with severity of the clinical signs (local swelling and changes in secretion). The concentration of lactoferrin was significantly higher in quarters with slight alterations of glandular tissue than in quarters with medium or severe alterations (P < 0.05). LPS-activities did not correlate with the severity of clinical signs. No differences in the concentration of lactoferrin or LPS-activities were seen between mastitis with positive and negative culture results. The concentration of lysozyme was even higher in culturally positive samples than in negative samples (P < 0.05). Results from this study indicate that the three factors examined did not impair the results of microbiological culture of milk samples from quarters with clinical mastitis.

Animals↗
PubMed2003

Characterization of the human lactoferrin (HLF) cell line HLFK1, generated in CBA mice.

A human lactoferrin-specific cell line was generated in CBA mice, sensitized with 200 microg HLF in Freund's complete adjuvant. HLFK1 cells derived from the lymph nodes of these mice were maintained using HLF as the antigen. HLF was added at the beginning of each 14-day restimulation cycle, at a concentration of 100 microg/ml. The presentation of the antigen to HLFK1 was demonstrated using glass-adherent lymphocytes from spleens (GAL) as the antigen-presenting cells (APC). The presentation of HLF by GAL was highly efficient; a very low concentration of the antigen (1 microg/ml) was enough to stimulate proliferation of the HLFK1 cell line. HLFK1 did not proliferate in the presence of ovalbumin or bovine lactoferrin (BLF), which is structurally related to HLF. However, we found that BLF caused a reduction in the proliferation of the HLFK1 cell line when BLF was added to the cultures together with the antigen - (HLF). On the other hand, proliferation of the HLFK1 cell line was not inhibited by pretreatment of the antigen-presenting cells or T cells with BLF. Therefore, we suggest that bovine lactoferrin may interfere with the binding or uptake of the antigen (HLF). Alternatively, BLF may nonspecifically inhibit the activation of the HLFK1 cell line.

Animals↗
PubMed2003

Interleukin-8, tumor necrosis factor-alpha, and lactoferrin in immunocompetent hosts with experimental and Brazilian children with acquired cryptosporidiosis.

To examine the importance of intestinal inflammation in the diagnosis and pathogenesis of human cryptosporidiosis, stools of healthy adult volunteers before and after experimental infection were tested for fecal lactoferrin, interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-alpha). Stool samples of Brazilian children with well-defined Cryptosporidium infection, with or without diarrhea, were also tested for IL-8 and TNF-alpha. Only one of the 14 volunteers challenged with Cryptosporidium had increased fecal lactoferrin. However, of 17 stool specimens from children with only Cryptosporidium infection from a previous study, 12 had mild to moderately elevated lactoferrin despite negative work-up for inflammatory enteritides. One of 10 adult volunteers who developed diarrhea with experimental cryptosporidiosis and three of 11 children with cryptosporidiosis and diarrhea had detectable fecal IL-8. The level of TNF-alpha was increased only in one of 14 volunteers and in none of the children. Although considered relatively non-inflammatory. cryptosporidiosis is often associated with mild inflammation, especially in children in an endemic area.

Adult↗
PubMedDate not supplied

[Lactoferrin assay in urethritis and urethral prostatitis].

An immunochemical study of prostatic secretions in 97 patients with urethritis and urethroprostatitis has detected a significant rise of lactoferrin level in mixed infections (trichomonads + chlamydia and trichomonads + uroplasma--17 patients) versus control (14 healthy males) and group as a whole. In the control group a mean lactoferrin level was 51.2 +/- 8.4 mg/l (12 mg/l-67.3 mg/l), in the group as a whole 106 +/- 41.5 mg/l (19.5 mg/l to 334.8 mg/l) in patients with mixed infection 221.25 (102.9 mg/l to 334.8 mg/l). The assessment of diagnostic significance of the immunochemical test for lactoferrin in detection of mixed infections in urethritis and urethroprostatitis has shown that in threshold level of 150 mg/l the test's specificity was 87.5%, sensitivity 94.1%, effectiveness 88.65%, prognostic value of positive result 61.5%, of negative result 98.59%; in threshold level 200 mg/l the respective values were 100, 52.9, 91.75, 100 and 90.9%. Practical application of the proposed immunochemical test in detection of mono- and mixed infection is discussed.

Adult↗
PubMed2003

[Role of lactoferrin in development of inflammation].

During acute inflammation, immune homeostasis is lost leading to destructive immunopathology. Homeostasis is normally dependent upon coordinated interactions among the various lymphoid, phagocytic and somatic cells that comprise the immune system. In general, these interactions are tightly regulated to obtain a balance between mechanisms necessary to eliminate harmful pathogens, and overaggressive responses leading to destruction of host tissue. Activation of immunoeffector cells results in pro-inflammatory cytokine up-regulation which in turn also activates the vascular endothelium. Through complex signaling, a positive feedback circuit is established which amplifies and sustains the activity of the inflammatory response resulting in the release of other cytokines and related molecules. If these responses are activated in an uncontrolled fashion with dissemination via the circulation, over the period of time, organs distant from the initial insult can be affected to produce multiple organ failure. Lactoferrin, an iron-binding glycoprotein, is considered an important mediator in host defense against the environmental insults in mammals. By virtue of iron sequestration lactoferrin can control the development of many oxidative stress-driven responses. The purpose of this review is to provide a comprehensive summary of research regarding lactoferrin and its role in homeostasis.

Animals↗
PubMed1992

Low density lipoprotein receptor-related protein and gp330 bind similar ligands, including plasminogen activator-inhibitor complexes and lactoferrin, an inhibitor of chylomicron remnant clearance.

The low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor (LRP) and gp330, two members of the low density lipoprotein receptor gene family, share a multitude of cysteine-rich repeats. LRP has been shown to act as an endocytosis-mediating receptor for several ligands, including protease-antiprotease complexes and plasma lipoproteins. The former include alpha 2-macroglobulin-protease complexes and plasminogen activator inhibitor-activator complexes. The latter include chylomicron remnant-like particles designated beta-very low density lipoproteins (beta-VLDL) complexed with apoprotein E or lipoprotein lipase. The binding specificity of gp330 is unknown. In the current studies we show that gp330 from rat kidney membranes binds several of these ligands on nitrocellulose blots. We also show that both LRP and gp330 bind an additional ligand, bovine lactoferrin, which is known to inhibit the hepatic clearance of chylomicron remnants. Lactoferrin blocked the LRP-dependent stimulation of cholesteryl ester synthesis in cultured human fibroblasts elicited by apoprotein E-beta-VLDL or lipoprotein lipase-beta-VLDL complexes. Cross-competition experiments in fibroblasts showed that the multiple ligands recognize at least three distinct, but partially overlapping sites on the LRP molecule. Binding of all ligands to LRP and gp330 was inhibited by the 39-kDa protein, which co-purifies with the two receptors, suggesting that the 39-kDa protein is a universal regulator of ligand binding to both receptors. The correlation of the inhibitory effects of lactoferrin in vivo and in vitro support the notion that LRP functions as a chylomicron remnant receptor in liver. LRP and gp330 share a multiplicity of binding sites, and both may function as endocytosis-mediating receptors for a large number of ligands in different organs.

Animals↗
PubMedDate not supplied

[Pharmacokinetics of human milk lactoferrin in intact mice and tumor-carrying animals].

Pharmacokinetics of iodine containing and native lactoferrin from human milk was studied in intact mice and the animals with Ehrlich ascites carcinoma. Both these antigens, native and I-lactoferrin, were similarly distributed in intact mice body. The same pharmacokinetics was found in tumor-bearing animals. Exogenous lactoferrin penetrated mainly into liver tissue, then simultaneously with bile--into small intestine and further into large intestine. Distinct accumulation of the glycoprotein was not found in tumor tissue.

Animals↗
PubMed1990

Electron spin echo envelope modulation evidence for carbonate binding to iron(III) and copper(II) transferrin and lactoferrin.

Iron binding to transferrin and lactoferrin requires a synergistic anion, which is carbonate in vivo. The anion is thought to play a key role in iron binding and release. To understand better the iron-carbonate interaction, experiments were performed with iron(III) and copper(II) complexes of human milk lactoferrin and serum transferrin with carbon-13-labeled carbonate. Modulation frequencies were present in the Fourier transforms of two-pulse and three-pulse electron spin echo envelope modulation data for the Fe(III) and Cu(II) complexes, consistent with binding of carbonate to both metals. The metal-13C interaction was similar for the lactoferrin and transferrin complexes. Spin coupling to the nitrogen of a coordinated histidine imidazole was observed for both metals. Both the metal-nitrogen and the metal-carbon spin coupling constants were about a factor of 5 smaller for the iron complexes than for the copper complexes, which indicated substantial similarity in the metal-carbonate and metal-imidazole binding for the two metals.

Carbonates↗
PubMed1990

Decreased lactoferrin content in granulocytes from subjects with Actinobacillus actinomycetemcomitans associated periodontal diseases.

Fourteen subjects were examined for lactoferrin content in PMNs of venous blood. Eight of the subjects were diagnosed localized juvenile periodontitis (LJP) and four adult periodontitis (AP), all having subgingival occurrence of Actinobacillus actinomycetemcomitans (A.a.). Two subjects had healthy gingival conditions and no detectable A.a. Deficiency or low PMN lactoferrin amounts were found in six of the eight subjects with LJP and in two of the subjects with AP. The reduced lactoferrin content in the PMNs was suggested to be depending on a cytotoxic factor produced by A.a. adding to an intrinsic PMN defect.

Actinobacillus↗
PubMed1989

Comparison of the electron spin echo envelope modulation (ESEEM) for human lactoferrin and transferrin complexes of copper(II) and vanadyl ion.

Copper(II) and vanadyl ions were bound to human milk lactoferrin or serum transferrin with carbonate or oxalate as the synergistic anion. Electron spin echo envelope modulation (ESEEM) due to nitrogen of a coordinated histidine imidazole was observed for both the copper and vanadyl complexes. For both metals, the modulation frequencies in the Fourier transforms of the data were similar for the two proteins and were weakly dependent on anion. When data in D2O/glycerol-d3 were compared with data in H2O/glycerol, the deep deuterium modulation indicated multiple exchangeable protons in the vicinity of the metals with at most one proton within about 2.9 A of the metal. The distribution of exchangeable protons around the metals as probed by ESEEM was the same, within experimental uncertainty, for the copper or vanadyl complexes with either carbonate or oxalate as the anion. When 13C-labeled oxalate was used as the synergistic anion, 13C-ESEEM was observed for both the copper and vanadyl complexes of lactoferrin and transferrin. The deeper 13C modulation for copper and vanadyl transferrin [13C]oxalate than for vanadyl transferrin [13C]carbonate suggests that both ends of the oxalate are bound to the metal in the transferrin and lactoferrin complexes.

Copper↗
PubMed1989

Myoepitheliomas and myoepithelial adenomas of salivary gland origin. Immunohistochemical evaluation of filament proteins, S-100 alpha and beta, glial fibrillary acidic proteins, neuron-specific enolase, and lactoferrin.

Immunohistochemical identification of keratin proteins (TK, KL1 and PKK1), vimentin, myosin, S-100 protein (using polyclonal antiserum) and S-100 alpha and beta subunits, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), lactoferrin, and lysozyme was made in myoepitheliomas, myoepithelial adenomas, and clear cell adenomas of salivary gland origin. Myoepithelioma cells were divided into two types: plasmacytoid cells, which showed great heterogeneity in terms of keratins and S-100 alpha and beta proteins and a lack of GFAP, NSE, lactoferrin, and lysozyme in most the cells, and fibrous and dendritic tumor cells, which displayed variable staining for keratin and S-100 alpha and beta proteins. Myoepithelial adenomas were composed of small-, intermediate-, and large-sized spindle cells that showed irregular positive reactions for keratins and S-100 alpha and beta. Immunohistochemical deposition of S-100 protein was restricted strongly to the dendritic cells present in hyalinous and myxomatous areas. Clear cell adenomas revealed uniformly slight staining of keratins and S-100 proteins, and negative staining or rarely positivity for GFAP, NSE, lactoferrin, and lysozyme. When the immunohistochemical deposition of these proteins was compared between normal glands and myoepithelial tumors, heterogeneity of expression of keratins, S-100 proteins, GFAP, and NSE was notable in the tumors. Progenitor cells of several kinds of myoepithelioma were suggested to be intercalated reserve cells, which are thought to be the same cell that gives rise to pleomorphic adenoma of salivary glands.

Adenoma↗
PubMedDate not supplied

[Expression of lactoferrin and myeloperoxidase genes in blasts of acute lymphoblastic leukemia].

The myeloperoxidase (MPO) and lactoferrin genes are strictly associated to the granulocytic differentiation pathway. Many reports show that immunologic and molecular cell markers, though to be lineage specific, are in fact expressed in cells of different lineages. We have identified lymphoid blast cell populations expressing the MPO gene at the mRNA level, but lacking any detectable MPO protein. We addressed this issue studying the expression of the MPO and lactoferrin genes in extremely homogeneous Acute Lymphoblastic Leukemia (ALL) blast cell populations. The study was carried out by solution hybridization of total cellular mRNA extracted from the leukemic populations with an antisense RNA transcribed by riboprobes. Either MPO or lactoferrin mRNAs were detectable in some ALL populations.

Gene Expression Regulation, Neoplastic↗
PubMed1986

Detection of localization and internalization of membrane DNA in the Tetrahymena by the lactoferrin--colloidal gold technique.

It is known that lactoferrin binds to DNA. In the present study a lactoferrin-gold complex bound initially to the ciliary membrane, then appeared in coated pits and intracytoplasmic vesicles. On treatment for 1 h, the gold particles could be detected near to the nucleus. The lactoferrin-gold complex neither bound to the surface, nor appeared in the cytoplasm of those cells which had been exposed to DNAse for pretreatment.

Animals↗
PubMed1979

Specificity of lactoferrin as an inhibitor of granulocyte-macrophage colony-stimulating activity production from fetal mouse liver cells.

Fetal mouse liver cultures capable of producing both erythropoietin (Ep) and granulocyte-macrophage colony stimulating activity (GM-CSA) were used to study the specificity of lactoferrin as an inhibitor of the production of GM-CSA. Both a granulocyte-derived colony-inhibiting activity (CIA) and lactoferrin inhibited GM-CSA production while having no effect on Ep production. These results demonstrate the specificity of lactoferrin for GM-CSA production.

Animals↗
PubMedDate not supplied

Tear lysozyme and lactoferrin levels in giant papillary conjunctivitis and vernal conjunctivitis.

We measured tear lysozyme by a radial immunodiffusion assay in patients with contact lens induced giant papillary conjunctivitis (GPC) and in patients with vernal conjunctivitis (VC). The VC and GPC patients had normal levels of tear lysozyme when compared to control individuals who did not have eye disease and to normal individuals who wore contact lenses without difficulty. In contrast, the tear concentration of lactoferrin (another important tear protein produced by the lacrimal glands) was reduced both in VC and GPC patients. Normal levels of tear lysozyme in the presence of reduced tear concentrations of lactoferrin may be a unique pattern in these two ocular conditions. The reduced tear levels of lactoferrin are probably not related to lacrimal gland dysfunction but to other factor(s) important in the pathogenesis of these two ocular disorders.

Conjunctivitis, Allergic↗
PubMed1988

[Degree of structural homology of lactoferrins from milk and neutrophilic granulocytes].

Some physico-chemical properties of human and pig lactoferrins from milk and neutrophilic granulocytes were compared. It was shown that the lactoferrins from different cell and tissue sources of the same species (humans or pigs) are identical in terms of electrophoretic mobility, molecular weight, iron-binding capacity, absorbance spectra, amino acid and sugar compositions and peptide maps. Human and pig lactoferrins show a high degree of structural homology (approximately 50%), but are immunochemically different.

Amino Acids↗
PubMed1986

[The effect of hormonal contraceptives and pregnancy on iron metabolism, plasma lactoferrin levels and granulocyte count in women].

Plasma iron, total iron-binding capacity, transferrin, serum ferritin, plasma lactoferrin and the number of circulating granulocytes were determined in 51 healthy, non-iron-deficient women. Blood was sampled at three stages of the menstrual cycle of 6 women with spontaneous menstruation and of 6 on low-estrogen hormonal contraception. Furthermore, 39 pregnant women were studied at three stages in the second half of uncomplicated pregnancy (13 women per stage). Women on oral contraceptives differed from those with spontaneous menstrual cycles in that they did not show a drop of plasma iron at menstruation, and, on the average, they had slightly higher serum ferritin concentrations, lower plasma-lactoferrin levels and a decreased number of circulating granulocytes. No significant difference was found with respect to total iron-binding capacity and transferrin concentration. In pregnancy, a progressive increase of total iron-binding capacity and transferrin, and an intermittent decline of serum-ferritin, followed by a rise shortly before delivery, were observed. Plasma lactoferrin increased in parallel with the number of circulating granulocytes. An attempt is made to separate findings that have to be attributed to a direct hormonal effect on iron metabolism from those that may depend on other factors.

Adult↗
PubMed1985

Lactoferrin serum levels in burned patients.

Twenty burned patients were studied (with mean body surface area burned 46.5%, mean age 25.4 years, and mean survival probability 78%), and lactoferrin, white-cells count and blood cultures were determined. Lactoferrin was detected more frequently (P less than 0.01) in the samples of patients with positive blood cultures. The role of lactoferrin in host defense mechanism and its possible function in sepsis is considered.

Adolescent↗