Human liver regeneration is characterized by the coordinated expression of distinct microRNA governing cell cycle fate.

In the absence of adequate compensatory regeneration, overwhelming liver damage can cause acute liver failure (ALF) and death without emergent liver transplantation (LT). Auxiliary LT produces satisfactory outcomes in this setting, with the prospect of native liver regeneration sustaining long-term survival. Since animal models only partially recapitulate human liver regeneration, we investigated the molecular mechanisms controlling it in this unique LT setting, as an exemplar of human liver regeneration. We demonstrate coordinated changes in expression of microRNA (miRNA) during regeneration that drive proliferation, innate immunity and angiogenesis. In contrast, failed regeneration in a similar cohort is associated with distinct miRNA enforcing cell cycle inhibition and DNA methylation. The miRNA expression associated with successful or failed regeneration when recapitulated in vitro, triggered expression of cardinal regeneration-linked genes promoting cell cycle entry or inhibition, respectively. Furthermore, inhibition of miRNA 150, 663 and 503, whose downregulation is associated with successful regeneration, induced cell proliferation which a key determinant of successful regeneration. Our data indicate that human liver regeneration may be orchestrated by distinct miRNA controlling key regeneration-linked processes including hepatocyte proliferation. To our knowledge this is the first characterization of molecular processes associated with human liver regeneration.

Patient perception of skin-cancer prevention and risk after liver transplantation.

INTRODUCTION: Sun exposure is a major risk factor for the development of skin cancer. This is particularly relevant in immunosuppressed liver-transplant recipients (LTRs). Preventative strategies may help minimize the skin-cancer risk in this patient group. METHODS: We assessed 670 patients in our post-transplant clinic, using questionnaires. Patient data were collected, and we assessed whether patients had received education (such as formal talks or information from transplant coordinators or from hepatologists) on skin, sun exposure and skin cancer. In a subset of 280 of the LTRs who responded, we recorded their recall of sun-protection advice and assessed the level of patient adherence to such advice. RESULTS: The response rate was 57.5% (349/607), with a mean responder age of 51.1 years (range 19-84) and an average post-transplant time of 7.1 years (range 0-27). In the recall assessment, 37.2% reported that they were given advice about their skin, while 18.1% were seen by a dermatologist, and education on sun exposure and the risks of skin cancer was given to 65.6% and 47.9%, respectively. Over three-quarters (78%; 185/280) of the patients used mechanical sun protection (i.e. hats/clothing), while 66% reported using sunscreen; 31.8% of these used a sunscreen of the recommended sun protection factor (SPF) of > 30. Twelve patients had developed squamous cell carcinoma after a mean of 10.9 years (1-23) post-transplant; half of these had used either no sunscreen or one with an SPF of < 15. CONCLUSIONS: Despite the fact that LTRs are given information on sun-exposure and SC before and after transplantation, recall of such advice and use of sun-protection methods was only moderate, indicating that regular reinforcement of SC education is needed.

Nature's loss, Immunologists gain?

Nature Reviews Molecular Cell Biology Nature Publishing Group (2000). ISSN 1471-0072. Monthly First there was Annual Reviews, then came the monthly Elsevier Trends Journals, both of which try to identify hot topics in their chosen fields. The Current Opinion journals followed several years later, and Current Opinion in Cell Biology is presently one of the highest 'impact factor' review journals, with a distinguished board of editors and advisors and a systematic approach to regular coverage of the major fields of cell biology. Important topics are visited once a year, whether or not something specially exciting happened in the last 12 months. Add to this list Seminars in Cell and Developmental Biology, the FASEB journal and the countless minireviews in 'real' journals, and you begin to wonder how anyone finds any time for doing experiments, or indeed reading the primary literature. So, into this already crowded field arrive three important newcomers: Nature Reviews in Molecular Cell Biology, Genetics, and Neurosciences, of which the first two will probably interest readers of Journal of Cell Science the most. Backed by the name and money of Nature and edited by experienced Nature staff, it is hard to see how these publications can possibly do other than succeed with writers and readers alike. What's inside the first issue? The cover of Nature Reviews in Molecular Cell Biology presents a 3-colour montage of a blue cell nucleus surrounded by splotches of green GPI-anchored GFP overlaid by orange actin stress fibres that seem to come from somewhere else. This image trails a comprehensive review from Kai Simons and Derek Toomre about Lipid Rafts. There are another five major review articles: calcium puffs and sparks, rings around DNA, HIV inhibitors, kinesin and the circadian clock provide a rich and varied mix of topics from authors who know what they're talking about. Surrounding this core is an entertaining mixture of 'highlights' at the front: news and views about a well-chosen selection of recent articles in the primary literature written by the three editors. These struck me as striking slightly too jokey a style. It is a terrible temptation and mistake in this kind of piece, I think, to equate lightheartedness with clarity. The sugar coating is more likely to irritate than enlighten. I would also question the wisdom, if it is indeed a policy, of only allowing editors to write in this section. I'm all for experienced writers writing, but I think I would prefer the variety of voice and authority evinced by the parental Nature News and Views. After the main reviews comes a section entitled 'perspectives', which include a 'Timeline' piece on Hayflick and his limit by Jerry Shay and Woodring Wright that I very much enjoyed, and a review (or Opinion) about cancer from Judah Folkman, Philip Hahnfeldt and Lynn Hlatky. In their own words, "the impetus for this Opinion article centres on the increasing awareness of the heterogeneity and instability of the cancer genome [. I]t is possible that suppressing this degenerative process may itself comprise an alternative constraint-based paradigm." The authors' fondness for portentous phrases of this kind rather spoiled their discussion for me. I also had trouble with an article on molecular computing. PCR reactions can solve the travelling salesman problem, it seems, but extremely slowly compared to a proper computer. The magazine has a nice heft to it, and is attractively designed and presented in glossy colour, although the main font is small enough to make reading difficult for your middle-aged reviewer in a particularly heavily overcast and rainy week in London. A first issue is supposed to be a kind of showcase, but if they can keep this up, the editors will surely have a success on their hands and you will probably be obliged to take out a personal subscription (£85), or persuade your library to part with £565. That's slightly cheaper than TiBS and a lot cheaper than Current Opinion in Cell Biology, both of which will have to run faster if they want to stay in the same place.

The Patient Requests Form: a way of measuring what patients want from their general practitioner.

A consumer-oriented approach to the delivery of health care and an understanding of the processes that influence clinical management decisions require the measurement of what patients seek when they consult their doctor. The present study completed the development of an instrument (the Patient Requests Form) that can quantify the intentions of patients attending their general practitioner. The Patient Requests Form was completed by 410 patients attending two general practices: one in an inner city area, the other in a small town. Principal components analysis revealed that the responses from each sample yielded identical components that described three distinct types of request: (i) for explanation and reassurance, (ii) for emotional support, and (iii) for investigation and treatment. Scales constructed to measure each type of request have high internal consistency while being sufficiently brief to be acceptable to general practice patients. The Patient Requests Form is a novel, convenient method to quantify the intentions of patients when they consult a general practitioner. It permits research into neglected aspects of consultation behaviour, including the factors that influence patients' intentions to seek different kinds of help and GPs' perceptions of these intentions.

Systematic review: the role of liver transplantation in the management of hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a major cause of morbidity and mortality worldwide. Liver transplantation offers a potential cure for this otherwise devastating disease. The selection of the most appropriate candidates is paramount in an era of graft shortage. AIM: To review systematically the role of liver transplantation in the management of HCC in current clinical practice. METHODS: An electronic literature search using PUBMED (1980-2010) was performed. Search terms included HCC, hepatoma, liver cancer, and liver transplantation. RESULTS: Liver transplantation is a highly successful treatment for HCC, in patients within Milan criteria (MC), defined as a solitary tumour ≤50 mm in diameter or ≤3 tumours ≤30 mm in diameter in the absence of extra-hepatic or vascular spread. Other eligibility criteria for liver transplantation are also used in clinical practice, such as the University of California, San Francisco criteria, with outcomes comparable to MC. Loco-regional therapies have a role in the bridging treatment of HCC by minimising wait-list drop-out secondary to tumour progression. Beyond MC, encouraging results have been demonstrated for patients with down-staged tumours. Post-liver transplantation, there is no evidence to support a specific immunosuppressive regimen. In the context of an insufficient cadaveric donor pool to meet demand, the role of adult living donation may be increasingly important. CONCLUSIONS: Liver transplantation offers a curative therapy for selected patients with HCC. The optimisation of eligibility criteria is paramount to ensure that maximum benefit is accrued. Although wait-list therapies have been incorporated into clinical practice, additional high quality data are required to support this strategy.

Nef triggers a transcriptional program in T cells imitating single-signal T cell activation and inducing HIV virulence mediators.

Gene expression profiling was used to explore the role of Nef in HIV. Nef induces a transcriptional program in T cells that is 97% identical to that of anti-CD3 T cell activation. This program is inhibited in the presence of cyclosporin. A requirement for TCR zeta and ZAP-70 is demonstrated for formation of the complete profile. Among eight factors particular to the anti-CD3 activation profile are IL16 and YY1, negative regulators of HIV transcription. In contrast, Nef exclusively upregulates factors positively regulating HIV, including Tat-SF1, U1 SNRNP, and IRF-2. New genes associated with Nef include CDK9, the induction of which enhances Tat function. Thus, Nef acts as a master switch early in the viral life cycle, forcing an environment conducive to dynamic viral production.

Acceleration of intracellular targeting of antigen by the B-cell antigen receptor: importance depends on the nature of the antigen-antibody interaction.

The B-cell antigen receptor (BCR) internalizes bound antigen such that antigen-derived peptides become associated with emigrating major histocompatibility complex (MHC) class II molecules for presentation to T cells. Experiments with B-cell transfectants reveal that BCR confers a specificity of intracellular targeting since chimeric antigen receptors which internalize antigen by virtue of a heterologous cytoplasmic domain do not necessarily give rise to presentation. In contrast, however, previous studies have shown that antigen binding to irrelevant cell surface molecules (e.g. transferrin receptor, MHC class I) can ultimately lead to presentation. The solution to this paradox appears to be that the intracellular targeting by BCR actually reflects an acceleration of antigen delivery. Depending on the nature of the BCR-antigen interaction, this accelerated targeting can be essential in determining whether or not internalization leads to significant presentation. Physiologically, the accelerated delivery of antigen by BCR could prove of particular importance early in the immune response when antigen-BCR interaction is likely to be poor.

B cells and professional APCs recruit regulatory T cells via CCL4.

Using gene expression profiling, we show here that activation of B cells and professional antigen-presenting cells (APCs) induces the expression of common chemokines. Among these, CCL4 was the most potent chemoattractant of a CD4+CD25+ T cell population, which is a characteristic phenotype of regulatory T cells. Depletion of either regulatory T cells or CCL4 resulted in a deregulated humoral response, which culminated in the production of autoantibodies. This suggested that the recruitment of regulatory T cells to B cells and APCs by CCL4 plays a central role in the normal initiation of T cell and humoral responses, and failure to do this leads to autoimmune activation.