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Differentiating osteoporotic vertebral fractures (OVF) from metastatic vertebral fractures (MVF) is difficult. A magnetic resonance imaging (MRI)-based score (META score) aiming to differentiate OVF and MVF was recently published; however, an independent agreement assessment is required before the score is used. We performed such independent agreement evaluation, including raters with different levels of training. Sixty-four patients with confirmed OVF or MVF were evaluated by six raters (three spine surgeons and three orthopaedic residents) using the META score. We used the intra-class correlation coefficient (ICC) to evaluate inter- and intra-observer agreement and the kappa statistic (κ) to determine the agreement for individual score criteria. We calculated the area under the receiver-operating characteristic curve (AUC) to establish the score accuracy. The inter-observer agreement was poor [ICC = 0.22 (0.12–0.33)]; spine surgeons [ICC = 0.75 (0.66–0.83)] had better agreement than that of residents [ICC = 0.06 (− 0.07 to 0.23)]. The intra-observer agreement was poor [ICC = 0.15 (− 0.04 to 0.30)]; both spine surgeons [ICC = 0.21 (0.05–0.41)] and residents exhibited poor agreement [ICC = − 0.06 (− 0.40 to 0.20)]. The agreement for each specific criterion varied from κ = 0.24 to κ = 0.38. The AUC was 0.57 (0.64 for spine surgeons and 0.51 for residents, p

Pectins are a type of soluble fiber present in natural and processed foods. Evidence regarding the effect of esterification degree of pectins on iron absorption in humans is scarce. In the present study, the effect of pectins with different degrees of esterification on non-heme iron absorption in women was evaluated. A controlled experimental study was conducted with block design, involving 13 apparently healthy, adult women. Each subject received 5 mg Fe (FeSO4) without pectin (control) or accompanied by 5 g citrus pectin, two with a low degree of esterification (27 and 36%), and one with a high degree of esterification (67 to 73%), each on different days. Each day, the 5 mg Fe doses were marked with radioactive 59Fe or 55Fe. Radioactivity incorporated into erythrocytes was determined in blood samples 14 days after the marked Fe doses were consumed. On days 18 and 36 of study, 30 and 20 mL blood samples were obtained, respectively, and blood sample radioactivity incorporated into erythrocytes was determined. Body iron status was determined from blood taken on day 18. Whole body blood volume was estimated for calculate iron bioavailability; it was assumed that 80% of absorbed radioactivity was incorporated into the Hb. All women participants signed an informed consent of participation at baseline. Iron bioavailability (mean geometric ±1 SD) alone (control) was 18.2% (12.3–27.1%), iron + pectin27 was 17.2% (10.2–29.2%), iron + pectin36 was 15.3% (9.5–24.6%), and iron + pectin67 was 19.5% (10.0–38.0%). No statistically significant differences between iron bioavailability (repeated measures ANOVA, p = 0.22) were observed. Pectin esterification degree does not influence the bioavailability of non-heme iron in women.

Divalent Metal Transporter 1 (DMT1) is an apical Fe transporter in the duodenum and is involved in endosomal Fe export. Four protein isoforms have been described for DMT1, two from mRNA with an iron responsive element (IRE) and two from mRNA without it. The sets of two begin in exon 1A or 2. We have characterized copper transport using mouse 2/-IRE DMT1 during regulated ectopic expression. HEK293 cells carrying a TetR:Hyg element were stably transfected with pDEST31 containing a 2/-IRE construct. (64)Cu(1+) incorporation in doxycycline treated cells exhibited 18.6 and 30.0-fold increases in Cu content, respectively when were exposed to 10 and 100 μM of extracellular Cu. Cu content was ~4-fold above that of parent cells or cells carrying just the vector. (64)Cu uptake in transfected cells pre-incubated with 5 μM of Cu-His revealed a Vmax and Km of 11.98 ± 0.52 pmol mg protein(-1) min(-1) and 2.03 ± 0.03 μM, respectively. Doxycycline-stimulated Cu uptake was linear with time. The rates of apical Cu uptake decreased and transepithelial transport increased when intracellular Cu increased. The optimal pH for Cu transport was 6.5; uptake of Cu was temperature dependent. Silver does not inhibit Cu uptake in cells carrying the vector. In conclusion, Cu uptake in HEK293 cells that over-expressed the 2/-IRE isoform of DMT1 transporter supports our earlier contention that DMT1 transports Cu as Cu(1+).

In the human gastrointestinal tract, trypsin and mucin may affect the absorption of heme iron. However, these interactions have not been well-established. We determined the effect of trypsin and mucin on heme iron absorption in humans. Design: Twenty-eight apparently healthy females participated in two studies (14 per study). Study A evaluated the effect of trypsin on iron bioavailability. Subjects ingested 100 mg trypsin and 1.7 g mucin on 5 mg heme iron bioavailability on days 1, 2, 14, and 15, respectively. In study B, which assessed the effect of mucin on heme iron bioavailability, the subjects ingested hemin, hemin plus mucin, hemoglobin (Hb), and Hb plus mucin, on days 1, 2, 14, and 15, respectively. Results: In study A, the geometric means ± 1 SD of heme iron absorption were 5.1 % (3.1–8.3), 2.9 % (1.6–5.1), 7.3 % (4.1–13.1), and 6 % (2.7–13) for hemin, hemin plus trypsin, Hb plus trypsin, and Hb plus mucin plus trypsin, respectively. In study B, the geometric means ± 1 SD of heme iron absorption were 16.4 % (10.5–25.7), 13.1 % (9.0–18.9), 13.7 % (9.0–20.7), and 11.8 % (7.6–18.3) for hemin, hemin plus mucin, Hb, and Hb plus mucin, respectively. The ratio increased when Hb plus trypsin was ingested and decreased when hemin plus trypsin was ingested. There were no differences in other ratios with respect to the ratio on day 1 (P

Introduction: Heme Fe is the main source of Fe in developed countries, because it has a better absorption than inorganic Fe. In the cell, heme-Fe is degradated to free Fe, Co and biliverdin for the microsomal enzyme heme oxygenase (HO). The role of HO1 in the intracellular Fe metabolism and heme-Fe uptake mechanisms by the cell it is unknown.

Background: Hem-iron is the main source of iron intake for humans in developed countries, which is best absorbed than inorganic iron (Fe). Iron deficiency is one of the most prevalent nutritional deficiencies in developing countries. One of the strategies to improve Fe nutrition is to increase hem-Fe intake in the population. Objective: To study in vitro the mechanisms of hem-Fe uptake and transport at the intestinal cells. Methods: Caco-2 Cells were grown in Iscove′s media, supplemented with 10% SFB, hem-Fe (Hb-Fe55) (0,1–100 uM Fe). We determined in cellular extracts, total intracellular Fe by AAE and heme oxygenase and DMT1(Divalent Metal Transporter 1) by Western Blot. We studied endocytic process, temperature effect and hem-Fe uptake and transport. The radioactivity was counted in the cells and in basolateral media. Results: Cells exposed to hem-Fe showed lower intracellular Fe than cells exposed to inorganic Fe. Hem-Fe uptake was inhibited by acidification and K+ depletion. The highest uptake and transport were observed in cells incubated with hem-Fe. Heme oxygenase 1 expression increased and DMT1 expression decreased when hem-Fe increased in the incubation media. Conclusions: Hem-Fe uptake in the intestinal epithelia cells would be by a inorganic Fe independent mechanism by a saturable and endocytic process dependent. Financing: FONDECYT 1030633 Chile.