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Biomedical subjects

E Ryan

Publications and source records attributed to E Ryan.

79 records · Page 5Linked to original sources

Increased duodenal DMT-1 expression and unchanged HFE mRNA levels in HFE-associated hereditary hemochromatosis and iron deficiency.

HFE-associated hereditary hemochromatosis is characterized by imbalances of iron homeostasis and alterations in intestinal iron absorption. The identification of the HFE gene and the apical iron transporter divalent metal transporter-1, DMT-1, provide a direct method to address the mechanisms of iron overload in this disease. The aim of this study was to evaluate the regulation of duodenal HFE and DMT-1 gene expression in HFE-associated hereditary hemochromatosis. Small bowel biopsies and serum iron indices were obtained from a total of 33 patients. The study population comprised 13 patients with hereditary hemochromatosis (C282Y homozygous), 10 patients with iron deficiency anemia, and 10 apparently healthy controls, all of whom were genotyped for the two common mutations in the HFE gene (C282Y and H63D). Total RNA was isolated from tissue and amplified via RT-PCR for HFE, DMT-1, and the internal control GAPDH. DMT-1 protein expression was additionally assessed by immunohistochemistry. Levels of HFE mRNA did not differ significantly between patient groups (P = 0.09), specifically between C282Y homozygotes and iron deficiency anemic patients, when compared to controls (P = 0.09, P = 0.9, respectively). In contrast, DMT-1 mRNA levels were at least twofold greater in patients with hereditary hemochromatosis and iron deficiency anemia when compared to controls (P = 0.02, P = 0.01, respectively). Heightened DMT-1 protein expression correlated with mRNA levels in all patients. Loss of HFE function in hereditary hemochromatosis is not derived from inhibition of its gene expression. DMT-1 expression in C282Y homozygote subjects is consistent with the hypothesis of a "paradoxical" duodenal iron deficiency in hereditary hemochromatosis. The observed twofold upregulation of the DMT-1 is consistent with the slow but steady increase in body iron stores observed in those presenting with clinical features of hereditary hemochromatosis.

Cation Transport Proteins↗

The celtic coincidence--the frequency and clinical characterisation of hereditary haemochromatosis in patients with coeliac disease.

BACKGROUND: Hereditary Haemochromatosis (HH) and Coeliac disease (CD) are common disorders in Northern European populations, particularly the Irish population. AIMS: To investigate whether there was increased frequency of the two common HFE gene mutations, C282Y and H63D, associated with HH amongst a cohort of CD patients, and to determine the penetrance of the HH associated genotypes in this cohort. METHODS: HFE genotypes of a cohort of CD patients were determined using standard PCR techniques. HFE allele frequencies were compared to those of a previously reported, ethnically similar, cohort of 800 neonates, using Fishers exact test. Patients with HH-associated genotypes were subsequently evaluated. RESULTS: The C282Y and H63D allele frequencies, 24/222 (11%) and 28/222 (13%) respectively, in the CD patients were similar to those of the neonatal group, 171/1600 (11%) and 242/1600 (15%). Eight patients had HH-associated genotypes, of which two demonstrated biochemical evidence of iron overload. CONCLUSION: The HFE mutations associated with Hereditary Haemochromatosis are not more common in Irish CD patients.

Celiac Disease↗

Juvenile hemochromatosis due to G320V/Q116X compound heterozygosity of hemojuvelin in an Irish patient.

Hemojuvelin (HJV) is a recently discovered gene responsible for 1q-linked juvenile hemochromatosis. The majority of mutations characterized in this gene are rare and private, except G320V, identified in patients from different countries. Here, we report the clinical features and the molecular study of a young Irish patient presenting with severe cardiac disease related to iron overload. We sequenced the coding region and the exon-intron boundaries of genes associated with juvenile hemochromatosis, HAMP and HJV encoding hepcidin and hemojuvelin respectively. Two heterozygous HJV mutations were identified: the G320V mutation and the new Q116X mutation that cause a premature stop codon in the protein. This finding increases the number of mutations identified in HJV gene and underlines that the G320V is a recurrent mutation, even in Northern Europe.

Adolescent↗

Fatty acid profile, tocopherol, squalene and phytosterol content of brazil, pecan, pine, pistachio and cashew nuts.

Nuts contain bioactive constituents that elicit cardio-protective effects including phytosterols, tocopherols and squalene. The objective of the present study was to determine the total oil content, peroxide value, fatty acid composition and levels of tocopherols, squalene and phytosterols in oil extracted from freshly ground brazil, pecan, pine, pistachio and cashew nuts. The total oil content of the nuts ranged from 40.4 to 60.8% (w/w) while the peroxide values ranged from 0.14 to 0.22 mEq O2/kg oil. The most abundant monounsaturated fatty acid was oleic acid (C18:1), while linoleic acid (C18:2) was the most prevalent polyunsaturated fatty acid. The levels of total tocopherols ranged from 60.8 to 291.0 mg/g. Squalene ranged from 39.5 mg/g oil in the pine nut to 1377.8 mg/g oil in the brazil nut. beta-Sitosterol was the most prevalent phytosterol, ranging in concentration from 1325.4 to 4685.9 mg/g oil. In conclusion, the present data indicate that nuts are a good dietary source of unsaturated fatty acids, tocopherols, squalene and phytosterols.

Anacardium↗