Defective bone morphogenic protein signaling underlies hepcidin deficiency in HFE hereditary hemochromatosis

Hereditary hemochromatosis (HH) is a common inherited iron overload disorder. The vast majority of patients carry the missense Cys282Tyr mutation of the HFE gene. Hepcidin, the central regulator of iron homeostasis, is deficient in HH, leading to unchecked iron absorption and subsequent iron overload. The bone morphogenic protein (BMP)/small mothers against decapentaplegic (Smad) signaling cascade is central to the regulation of hepcidin. Recent data from HH mice models indicate that this pathway may be defective in the absence of the HFE protein. Hepatic BMP/Smad signaling has not been characterized in a human HFE-HH cohort to date. Hepatic expression of BMP/Smad-related genes was examined in 20 HFE-HH males with significant iron overload, and compared to seven male HFE wild-type controls using quantitative real-time reverse transcription polymerase chain reaction. Hepatic expression of BMP6 was appropriately elevated in HFE-HH compared to controls (P = 0.02), likely related to iron overload. Despite this, no increased expression of the BMP target genes hepcidin and Id1 was observed, and diminished phosphorylation of Smad1/Smad5/Smad8 protein relative to iron burden was found upon immunohistochemical analysis, suggesting that impaired BMP signaling occurs in HFE-HH. Furthermore, Smad6 and Smad7, inhibitors of BMP signaling, were up-regulated in HFE-HH compared to controls (P = 0.001 and P = 0.018, respectively).

CONCLUSION

New data arising from this study suggest that impaired BMP signaling underlies the hepcidin deficiency of HFE-HH. Moreover, the inhibitory Smads, Smad6, and Smad7 are identified as potential disruptors of this signal and, hence, contributors to the pathogenesis of this disease.

Options for decentralized testing of suspected secondary outbreaks of foot-and-mouth disease

This article reviews the options for use of virus detection techniques for decentralized testing of samples from suspected secondary outbreaks of foot-and-mouth disease (FMD). These options have been expanded by the advent of new tests including disposable lateral flow devices (LFDs) that detect viral proteins and portable RT-PCR equipment that detects viral RNA. LFDs have been developed with similar sensitivity to antigen detection ELISA but with the ability to provide a result 1-30 min after the addition of epithelium or vesicular fluid. Portable RT-PCR platforms are being developed that can detect FMD viral RNA in blood, epithelium or other materials with minimal sample processing and with high sensitivity, in as little as 60 min in some cases. These devices may be used on infected farms as pen-side tests, in regional, local or mobile laboratories, or in National Reference Laboratories (NRL). Advantages and disadvantages of different testing options are considered to inform decisions on the optimal strategies for different national circumstances. Issues include validation and quality control, containment needs, availability of test devices and reagents, the decision tree for declaring an outbreak, training issues and provision of samples for subsequent viral characterization. Tests to confirm the diagnosis of the index case of an outbreak of FMD should continue to be carried out in the NRL.

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.

The evaluation of biologically important trace metals in liver, kidney and breast tissue

The levels of iron (Fe), copper (Cu), zinc (Zn) and potassium (K) have been measured in normal and malignant liver and kidney tissue using X-ray fluorescence. Zn was reduced in liver and kidney tumours by 63% and 26%, respectively. Fe, Cu and K were increased in kidney tumours by 150%, 8% and 90%, and reduced in liver tumours by 76%, 29% and 43%. A synchrotron microprobe was used to map calcium (Ca), Fe, Cu and Zn in breast tissue. The distributions were compared to reference images and higher concentrations of metals correlated with areas of cancer cells. The average increase of Ca, Fe, Cu and Zn concentrations in areas of malignancy were 70%, 43%, 53% and 87%.

Modelling studies to estimate the prevalence of foot-and-mouth disease carriers after reactive vaccination

Foot-and-mouth disease (FMD) is a highly contagious and economically significant viral disease of cloven-hoofed animals. Vaccination can be used to help restrict the spread of the infection, but evidence must be provided to show that the infection has been eradicated in order to regain the FMD-free status. While serological tests have been developed, which can identify animals that have been infected regardless of vaccination status, it is vital to know the probable prevalence of herds with FMD carriers and the within-herd prevalence of those carriers in order to design efficient post-epidemic surveillance strategies that establish freedom from disease. Here, we present the results of a study to model the expected prevalence of carriers after application of emergency vaccination and the impact of this on the sensitivity of test systems for their detection. Results showed that the expected prevalence of carrier-containing herds after reactive vaccination is likely to be very low, approximately 0.2%, and there will only be a small number of carriers, most likely one, in the positive herds. Therefore, sensitivity for carrier detection can be optimized by adopting an individual-based testing regime in which all animals in all vaccinated herds are tested and positive animals rather than herds are culled.

A study of 54 cases of left displacement of the abomasum: February to July 2005

Fifty-four cows with left displacement of the abomasum (LDA) submitted to the hospital facility at Riverview Veterinary Clinic from February to July 2005 were treated by right flank laparotomy and omentopexy. Five cows died (a survival rate 90.7%) and one cow (1.8%) was culled due to recurrence of the LDA post-operatively. Forty-one cows (76%) returned to good production post-operatively. Thirty-nine cows (72%) were pregnant six months after corrective surgery.

Phytosterol, squalene, tocopherol content and fatty acid profile of selected seeds, grains, and legumes

The unsaponifiable lipid fraction of plant-based foods is a potential source of bioactive components such as phytosterols, squalene, and tocopherols. The objective of the present study was to determine the levels of phytosterols, and squalene, as well as tocopherols (alpha and beta + gamma) in selected grains, seeds, and legumes. The method comprised acid hydrolysis and lipid extraction followed by alkaline saponification, prior to analysis by HPLC. In addition, the fatty acid profile of the foods was determined via total lipid extraction, fatty acid derivitisation and GC analysis. In general, beta-sitosterol was the most prevalent phytosterol, ranging in concentration from 24.9 mg/100 g in pumpkin seed to 191.4 mg/100 g in peas. Squalene identified in all foods examined in this study, was particularly abundant in pumpkin seed (89.0 mg/100 g). The sum of alpha- and beta+ gamma-tocopherols ranged from 0.1 mg/100 g in rye to 15.9 mg/100 g in pumpkin seeds. Total oil content ranged from 0.9% (w/w) in butter beans to 42.3% (w/w) in pumpkin seed and the type of fat, in all foods examined, was predominantly unsaturated. In conclusion, seeds, grains, and legumes are a rich natural source of phytosterols. Additionally, they contain noticeable amounts of squalene and tocopherols, and in general, their fatty acid profile is favorable.

Foot-and-Mouth Disease Virus Crosses the Placenta and Causes Death in Fetal Lambs

Eighteen pregnant sheep, six at 45 days gestation and twelve at 75 days gestation, were infected with foot-and-mouth disease virus (FMDV) type O UKG 34/2001. Two sheep from each gestational group were killed at 2, 4, and 7 days post-inoculation (dpi). Three sheep, pregnant for 75 days at infection, were killed at 17 and 18 dpi. Real-time reverse-transcriptase polymerase chain reaction (RT-PCR) and virus isolation (VI) were used to detect viral RNA and infectious virus, respectively, in fetal tissues taken post mortem. Eleven fetuses were obtained from the six sheep inoculated at day 45 of gestation. Of these, two of three fetuses at 2 dpi had viral RNA detected by RT-PCR and virus was detected in one by VI. Viral RNA was detected in two of four fetuses at 4 dpi, while viral RNA and virus were detected in all four fetuses at 7 dpi. No gross abnormalities were evident in these fetuses. In the group inoculated at day 75 of gestation, viral RNA was detected in three of four fetuses at 4 dpi. Virus and viral RNA were detected in three of four fetuses at 7 dpi. Of the seven fetuses examined at 17 and 18 dpi, viral RNA was detected in five, and four of these had died in utero. Gross abnormalities including haemorrhage and oedema in a number of tissues were evident in many of the fetuses in this group, but no vesicular lesions were found. Viral RNA and virus were detected in the amniotic fluid associated with infected fetuses. This study is the first to demonstrate that FMDV may cause transplacental infection and fetal death.

Justifying adjuvant chemotherapy in breast cancer: a survey of women and healthcare professionals

AIM

The absolute survival gains required to make adjuvant chemotherapy acceptable to women are unknown. We questioned women and healthcare professionals on the absolute survival benefits required to make adjuvant chemotherapy acceptable.

METHODS

A cohort of 1000 Irish women and 402 UK nurses and surgeons were invited to choose an absolute survival advantage sufficient to justify adjuvant cytotoxic chemotherapy. The non-physician cohort included women with a history of cancer, female medical healthcare professionals and women with no personal or professional experience of cancer.

RESULTS

Eight hundred and thirty-five women completed the questionnaire; 769, 651 and 413 said they would accept chemotherapy for a 10%, 5% and 1% survival advantage, respectively. There was a significant difference in women's preferences depending on their personal and professional experience of cancer. Eighty-nine women had personal experience of chemotherapy and these women were more likely to accept chemotherapy for any survival advantage (88, 87 and 66 for a 10%, 5% and 1% survival advantage, respectively; p=0.0023; Chi(2)). Surgeons and nurses were less likely to accept chemotherapy for smaller absolute survival advantages.

CONCLUSIONS

This study confirms that women require modest absolute gains to choose adjuvant chemotherapy. The pattern of acceptance differs significantly between those with professional experience of cancer, a personal history of chemotherapy use and a history of cancer or not.

Hepatic iron metabolism gene expression profiles in HFE associated Hereditary Hemochromatosis

BACKGROUND

Individuals with pathogenic mutations in HFE, hemojuvelin (HJV) and transferrin receptor 2 (TfR2) have low levels of hepcidin, but little is known about the hepatic expression of these molecules in patients with physiological iron overload or HFE associated Hemochromatosis (HH).

AIMS

To examine the hepatic mRNA expression of iron homeostasis genes in patients with HH, physiological iron overload and healthy controls.

PATIENTS

Untreated C282Y homozygous HH patients (n=20) with elevated serum ferritin (SF) and patients with physiological iron overload (n=12) with positive hepatocellular iron staining and negative HFE mutation analysis were evaluated. The control cohort (n=10) had normal iron parameters, negative HFE mutation analysis and negative hepatocellular iron staining.

METHODS

Hepcidin, HJV (hemojuvelin), TfR2 (transferrin receptor 2), HFE, IL6 (interleukin 6) and ferroportin mRNA expression patterns were evaluated using quantitative real-time PCR.

RESULTS

Physiological iron overload led to significantly upregulated hepcidin, HJV and ferroportin mRNA expression while TfR2 expression was not significantly different to controls. In contrast, HFE associated iron overload failed to induce hepcidin or HJV. TfR2 mRNA expression was significantly reduced when compared to controls. Ferroportin expression in HH was comparable to that found in physiological iron overload. Neither HFE nor IL6 expression was altered by variation in iron status.

CONCLUSIONS

These findings suggest that patients with HH, in contrast to those with physiological iron overload, have a weakened TfR2 sensing mechanism that leads to the lack of induction of hepcidin and HJV. The C282Y HFE mutation does not appear to impede the hepatocellular iron export function of ferroportin.

Mitochondrial cytopathies, phenotypic heterogeneity and a high incidence

Mitochondrial respiratory chain disorders account for significant and varied presentations in paediatric practice. The true prevalence of these disorders in the paediatric population is still not well documented with predicted geographic variation. We report a retrospective analysis over a seven year period of cases presenting to a tertiary care centre and associated clinical features. The overall prevalence of mitochondrial disorders in our population is higher than expected (1/9,000 births), explained in part by multiple presentations in a consanguineous subgroup of the population (Irish travellers).

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.