The role of microRNA in nutritional control

MicroRNAs (miRNAs) are one of a growing class of noncoding RNAs that are involved in the regulation of a wide range of metabolic processes including cellular differentiation, cell proliferation and apoptosis. The generation of miRNA is regulated in complex ways, for example by small interfering RNAs (small nucleolar and nuclear RNAs) and various other metabolites. This complexity of control is likely to explain how a relatively small part of the DNA that codes for proteins has enabled the evolution of such complex organisms as mammals. Non-protein-coding DNA is therefore thought to carry the memory of early evolutionary steps that led to progressively complex metabolic controls. Clinically, miRNAs are becoming increasingly important following the recognition that some congenital abnormalities can be traced to defects in miRNA processing. The potential for manipulating metabolism and affecting disease processes by the pharmaceutical or biological targeting of specific miRNA pathways is now being tested. miRNAs are also released into the extracellular milieu after packaging by cells into nano-sized extracellular vesicles. Such vesicles can be taken up by adjacent and possibly more distant cells, thereby allowing coordinated intercellular communication in specific tissues. Extracellular miRNAs found in the blood stream may also serve as novel biomarkers for both diagnosing specific forms of cancer and assessing the likelihood of metastasis, and as powerful prognostic indices for various cancers. Here, we discuss the role of intracellular and extracellular miRNAs in nutritional control of various (patho)physiological processes. In this review, we provide an update of the presentations from the 25th Marabou Symposium (Stockholm, 14-16 June 2013) entitled 'Role of miRNA in health and nutrition', attended by 50 international experts

Developmental toxicity in rats of a hemoglobin-based oxygen carrier results from impeded function of the inverted visceral yolk sac

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Infusion HBOC into pregnant rats causes developmental toxicity.

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Sensitive from GD 7 to 11 when inverted yolk sac placenta (invYSP) supplies nutrition.

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Controls for protein content, oncotic properties and Hb show effects are due to Hb.

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Whole embryo culture verified HBOC interference with invYSP function.

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Humans lack invYSP and are unlikely to be affected by HBOC.

HBOC-201 is a bovine-derived, cross-linked, and stabilized hemoglobin (250 kDa) in physiological saline. Daily intravenous infusions of HBOC (1.95, 3.90, or 5.85 g/kg/day) during gestational days (GDs) 6–18 in Sprague-Dawley rats caused fetal mortality, reduced birth weight, and malformations. Subsequent single-day infusions (5.85 g/kg/day) showed that developmental toxicity was limited to GDs 7–9 when histiotrophic nutrition via the inverted visceral yolk sac (invVYS) is essential. Histiotrophic nutrition is receptor-mediated endocytosis of bulk maternal proteins and subsequent lysosomal degradation providing amino acids and other nutrients for embryonic growth. Controls for protein content, oncotic properties, and hemoglobin content indicated that toxicity was due to hemoglobin. Rat whole embryo cultures verified HBOC interference with invVYS transport capacity and resultant deficient embryonic nutrition. These mechanisms of action are not expected to impact human development based on differences in VYS morphology and function, although a complete understanding of early human embryonic nutrition is lacking.

The influence of FDG PET-CT on the detection of extrahepatic disease in patients being considered for resection of colorectal liver metastasis

INTRODUCTION

The aim of this study was to evaluate the influence of flurodeoxyglucose positron emission tomography computed tomography (FDG PET-CT), as an adjunct to conventional CT staging, in the detection of extrahepatic disease in patients with potentially resectable colorectal liver metastasis.

METHODS

Overall, 133 consecutive patients with colorectal liver metastases staged with CT and PET-CT referred to the East Lancashire regional hepatobiliary multidisciplinary team over a two-year period were included in this study. Abnormal findings on PET-CT were correlated with follow-up imaging and/or histology. All imaging was reviewed by specialist hepatobiliary radiologists for the presence/absence of extrahepatic disease. The influence of the PET-CT findings was categorised for each patient in relation to operability and other significant findings.

RESULTS

PET-CT had a major impact on staging of extra hepatic disease in 20% of patients, in comparison with the initial CT. Six per cent of patients were upstaged from operable CT findings to inoperable findings on PET-CT because of the discovery of inoperable occult extrahepatic disease. Five per cent had operable local regional nodal disease detected on PET-CT. A further 3% had premalignant colorectal lesions detected on PET-CT. Six per cent of patients were downstaged from indeterminate or suspected inoperable CT findings to operable findings on PET-CT.

CONCLUSIONS

The use of PET-CT in this setting may prevent futile operations, guide the resection of local regional nodal disease and downstage a number of patients thought to have extrahepatic disease on conventional imaging. This study has shown similar results to other recent studies and supports the use of PET-CT as a necessary staging modality in patients with potentially resectable colorectal liver metastases.

Sleep disturbance in adults with cancer: a systematic review of evidence for best practices in assessment and management for clinical practice

Sleep disturbance is prevalent in cancer with detrimental effects on health outcomes. Sleep problems are seldom identified or addressed in cancer practice. The purpose of this review was to identify the evidence base for the assessment and management of cancer-related sleep disturbance (insomnia and insomnia syndrome) for oncology practice. The search of the health literature included grey literature data sources and empirical databases from June 2004 to June 2012. The evidence was reviewed by a Canadian Sleep Expert Panel, comprised of nurses, psychologists, primary care physicians, oncologists, physicians specialized in sleep disturbances, researchers and guideline methodologists to develop clinical practice recommendations for pan-Canadian use reported in a separate paper. Three clinical practice guidelines and 12 randomized, controlled trials were identified as the main source of evidence. Additional guidelines and systematic reviews were also reviewed for evidence-based recommendations on the assessment and management of insomnia not necessarily in cancer. A need to routinely screen for sleep disturbances was identified and the randomized, controlled trial (RCT) evidence suggests benefits for cognitive behavioural therapy for improving sleep quality in cancer. Sleep disturbance is a prevalent problem in cancer that needs greater recognition in clinical practice and in future research.

Anaesthetic management of an obstetric patient with variegate porphyria

Porphyria is an uncommon disease that can produce life-threatening attacks with a mortality rate of up to 10%, specifically as the result of administration of porphyrinogenic medications. In obstetric anaesthesia there are many situations where drugs are given in an emergency and it is therefore important to be prepared for complications to avoid inadvertently inducing an iatrogenic porphyric crisis. We discuss the case of a 20-year-old nulliparous woman with variegate porphyria who required an emergency caesarean section in labour, and the drugs that are commonly used in obstetric practice.