Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Capillary endothelial surface charge was investigated by perfusing the intestinal circulation of anesthetized rats in situ with 0.1 or 10 mg/ml native ferritin (NF, pI = 3.8-4.2) or with 0.1 mg/ml cationized ferritin (CF, pI greater than 10.0) for 5 min, with or without 5% Dextran 40. Ferritin binding was quantified by electron microscopy. All electron micrographs of capillaries perfused with NF showed some NF binding. Mean NF particle densities (particles/microns) were significantly greater at vesicle necks (PDv) than elsewhere on the endothelial surface (PD). Capillaries perfused with CF showed binding in only 60% of the transverse sections examined. The binding was very marked in a large proportion of these vessels. Mean CF particle densities were significantly greater at fenestrae (PDf) than elsewhere. These results demonstrate that mucosal capillaries have a variable negative electrostatic charge on the endothelial surface and support the hypothesis that some vesicle diaphragms act as preferential attractors for anionic macromolecules. Such structures could promote transendothelial vesicular transport of albumin. Dextran significantly decreased PD for NF from 25.4 +/- 2.4 (SEM) to 13.1 +/- 0.9 and PD, PDv, and PDf for CF from 45.9 +/- 4.6 to 31.0 +/- 2.7, from 62.1 +/- 6.2 to 43.6 +/- 5.4, and from 152.9 +/- 15.5 to 114.5 +/- 8.6, respectively. The above responses result from dextran's weak interaction with the endothelial surface. Dextran reduces access of ferritin molecules to the cell surface by steric hindrance and/or electrostatic shielding of the glycocalyx.
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PMID:Endothelial surface charge of intestinal mucosal capillaries and its modulation by dextran. 171 53

Alveolar macrophages (AM) contain iron and ferritin, and concentrations of both are increased in AM of smokers compared with nonsmokers. Ferritin stores iron in a nontoxic form but can release iron in the presence of reducing agents and thereby catalyze the generation of toxic hydroxyl radicals via the Haber-Weiss reaction. Two distinct isoferritins are found in peripheral monocytes, L ferritin and H ferritin. H ferritin is the predominant isoferritin in human monocytes and is more effective than L ferritin in detoxifying iron in vitro. In this study we quantitated content of H and L ferritins, transferrin, and iron in AM recovered by bronchoalveolar lavage (BAL) of 24 subjects, including eight nonsmokers, eight smokers with normal spirometry, and eight smokers with chronic airflow obstruction (CAO). Of total AM ferritin in nonsmokers 95% was composed of L ferritin. Smokers without CAO demonstrated a 6.5-fold increase in the AM content of L ferritin (1,886 +/- 266 versus 290 +/- 51 ng, mean +/- SEM; p less than 0.0001) and a 3.8-fold increase in H ferritin (61 +/- 18 versus 16 +/- 2 ng per 1 x 10(6) AM, p less than 0.01) compared with nonsmokers. Compared with smokers without CAO, AM recovered from smokers with CAO demonstrated a greater increase in L ferritin (5,059 +/- 493 versus 1,886 +/- 266 ng per 1 x 10(6) AM, p less than 0.002) but a similar increase in H ferritin (64 +/- 8 versus 61 +/- 18 per 1 x 10(6) AM).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Alveolar macrophage content of isoferritins and transferrin. Comparison of nonsmokers and smokers with and without chronic airflow obstruction. 173 35

Patients on chronic hemodialysis often need blood transfusions due to erythropoietin deficiency. Even after successful kidney transplantation iron overload may persist. Former histological studies have revealed siderosis of the liver in 69% of all patients whose serum ferritin was above 1100 ng/ml. The aim of the present study was to evaluate the influence of iron overload on liver function. In 146 symptom free patients with renal allografts serum ferritin was determined to detect possible iron overload. Serum ferritin between 4 and 5480 ng/ml were found (women: 358.7 +/- 105.3; men 282.4 +/- 63.3 ng/ml; x +/- SEM). Twelve patients (8.1%) had ferritin levels higher than 1100 ng/ml. These twelve patients as well as another group of eight patients with renal allografts whose serum ferritin was known to be higher than 1100 ng/ml were included for further evaluation. Their data were matched and compared with those of a control group also patients with renal allograft (same age and sex) whose serum ferritin was lower than 1100 ng/ml. Transaminases (SGPT 22.6 +/- 3.6 vs. 15.4 +/- 6.0 U/l; SGOT 14.7 +/- 2.0 vs. 13.0 +/- 4.8 U/l) and plasma glucose (90.5 +/- 7.1 vs. 76.8 +/- 3.7 mg/dl) were found to be significantly higher (p less than 0.05) in patients with serum ferritin levels above 1100 ng/ml. Elevated transaminases were significantly more frequent in patients with high serum ferritin (9 vs. 2; p less than 0.02) as compared with the control. Ferritin levels significantly correlated with the number of preceding blood transfusions (p less than 0.002). Hbs-persistence was detected in six out of 20 patients with high ferritin levels but only in one out of 20 in the control group (p less than 0.05) whereas anti-Hbs prevalence was not different in the two groups. These data indicate that chronic iron overload should be considered as a possible cause of chronic liver disease in patients with renal allografts.
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PMID:[Prevalence, causes and effects of increased iron storage in patients with kidney transplantation]. 223 9

An analytical SEM equipped with an above-the-lens detector, an in-the-lens specimen stage and a high brightness LaB6 emitter was used to produce a specimen-specific, secondary electron-I (SE-I) signal for recording edge brightness contrast with high intensity on small particles at high magnification (200,000). The SE-I edge brightness contrast produced from 20-40 nm colloidal gold on silicon wafers was useful for estimating instrument resolution since the edge brightness is the sum of the SE-I signal range (approximately equal to 1 nm) and the beam diameter. LaB6 crystal saturation and gun conditions were determined in order to minimize the probe diameter at the first cross-over position. Ferritin particles also on the silicon wafers were imaged by adjustments of the gun bias voltage conditions. Establishment of these conditions was useful for high resolution SEM studies of appropriately coated bulk biological specimens.
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PMID:Conditions required for detection of specimen-specific SE-I secondary electrons in an analytical SEM. 274 38

We have investigated the regulation of key human iron binding proteins in mononuclear phagocytes by IFN gamma and iron transferrin. In a previous study, we demonstrated that IFN gamma downregulates the expression on human monocytes of transferrin receptors, the major source of iron for the cell. In the present study, we show that IFN gamma also downregulates the intracellular concentration of ferritin, the major iron storage protein in the cell. By radioimmunoassay, the mean ferritin content of nonactivated monocytes was 361 +/- 107 fg/monocyte (mean +/- SEM) whereas the mean ferritin content of IFN gamma-activated monocytes was 64 +/- 13 fg/monocyte, an 82% reduction with activation (P < 0.01, t test). Consistent with its downregulating effect on these iron proteins, IFN gamma treatment also results in decreased iron incorporation. IFN gamma-activated monocytes incorporated 33% less iron from 59Fe-transferrin than nonactivated monocytes (P < 0.05, t test). Gel filtration chromatography revealed that incorporated iron is located primarily in ferritin in both nonactivated and IFN gamma-activated monocytes. Ferritin in IFN gamma-activated monocytes is saturated with approximately three times as much 59Fe as ferritin in nonactivated monocytes. We have also explored the effect of iron transferrin on transferrin receptor expression and intracellular ferritin content in human monocytes. We have found that iron transferrin markedly upregulates both transferrin receptor expression and intracellular ferritin content in both nonactivated (2.3- and 1.3-fold, respectively) and IFN gamma-activated (3.4- and 2.9-fold, respectively) monocytes. This study demonstrates that transferrin receptor expression and intracellular ferritin content in human monocytes is unidirectionally and coordinately upregulated by iron transferrin and unidirectionally and coordinately downregulated by IFN gamma.
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PMID:Regulation of transferrin receptor expression and ferritin content in human mononuclear phagocytes. Coordinate upregulation by iron transferrin and downregulation by interferon gamma. 845 71

The role of ferritin in fibrogenesis of liver parenchyma in patients with alcoholic liver disease has been investigated in previous studies. Ferritin was shown to be an indirect marker of ferum deposition in liver parenchyma in alcohol liver disease. The aim of the present study was to examine the role of nitric oxide (NO) in the pathogenesis of alcoholic liver disease as well as the influence of NO on iron (ferritin) metabolism in patients with alcoholic liver disease. Serum concentrations of NO and iron markers (iron, total iron binding capacity, ferritin) were measured in 30 male patients (aged 20-60 years) with alcoholic liver disease, as well as from a control group (30 male patients (aged 20-60 years) without liver disease). NO concentration was detected by measuring production of nitrates and nitrites using classical colorimetric Griess reactions. There was a statistically significant increase in serum NO concentration in patients with alcoholic liver disease compared to the control group (mean +/- SEM; 41,2 +/- 25,3 vs. 28,9 +/- 12,3 mmol/dm3, respectively; p<0,03). Similarly, serum iron levels (18,7 +/- 8,2 vs. 13,2 +/- 10,2 g/100 cm3, respectively; p<0,03) and serum total iron binding capacity (51,3 +/- 13,9 vs. 41,4 +/- 11,4 micromol/dm3, respectively; p<0,005) were also significantly higher in patients with alcoholic liver disease compared to control patients. The serum concentration of ferritin was 27% higher in patients with alcoholic liver disease than in the control group; however this was not statistically significant (283,2 +/- 291,0 vs. 222,9 +/- 252,0 g, respectively; p<0,4). There was no correlation between NO and ferritin in the investigated groups. These results suggest a possible role of NO and iron in the pathogenesis of alcoholic liver disease. NO and iron may be used as non-invasive predictors of liver damage. Also the role of iron in sera, and its deposition in liver parenchyma, could be used in clinical practice, especially in regards to assessing the fibrogenesis of liver parenchyma induced by ferritin.
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PMID:The role of nitric oxide and ferritin in the pathogenesis of alcoholic liver disease: a controlled clinical study. 1975 74