Should patients with self-inflicted illness receive lower priority in access to healthcare resources? Mapping out the debate.

The distribution of scarce healthcare resources is an increasingly important issue due to factors such as expensive 'high tech' medicine, longer life expectancies and the rising prevalence of chronic illness. Furthermore, in the current healthcare context lifestyle-related factors such as high blood pressure, tobacco use and obesity are believed to contribute significantly to the global burden of disease. As such, this paper focuses on an ongoing debate in the academic literature regarding the role of responsibility for illness in healthcare resource allocation: should patients with self-caused illness receive lower priority in access to healthcare resources? This paper critically describes the lower priority debate's 12 key arguments and maps out their relationships. This analysis reveals that most arguments have been refuted and that the debate has stalled and remains unresolved. In conclusion, we suggest progression could be achieved by inviting multidisciplinary input from a range of stakeholders for the development of evidence-based critical evaluations of existing arguments and the development of novel arguments, including the outstanding rebuttals.

Clinician gate-keeping in clinical research is not ethically defensible: an analysis.

Clinician gate-keeping is the process whereby healthcare providers prevent access to eligible patients for research recruitment. This paper contends that clinician gate-keeping violates three principles that underpin international ethical guidelines: respect for persons or autonomy; beneficence or a favourable balance of risks and potential benefits; and justice or a fair distribution of the benefits and burdens of research. In order to stimulate further research and debate, three possible strategies are also presented to eliminate gate-keeping: partnership with professional researchers; collaborative research design and clinician education.

UBF levels determine the number of active ribosomal RNA genes in mammals.

In mammals, the mechanisms regulating the number of active copies of the approximately 200 ribosomal RNA (rRNA) genes transcribed by RNA polymerase I are unclear. We demonstrate that depletion of the transcription factor upstream binding factor (UBF) leads to the stable and reversible methylation-independent silencing of rRNA genes by promoting histone H1-induced assembly of transcriptionally inactive chromatin. Chromatin remodeling is abrogated by the mutation of an extracellular signal-regulated kinase site within the high mobility group box 1 domain of UBF1, which is required for its ability to bend and loop DNA in vitro. Surprisingly, rRNA gene silencing does not reduce net rRNA synthesis as transcription from remaining active genes is increased. We also show that the active rRNA gene pool is not static but decreases during differentiation, correlating with diminished UBF expression. Thus, UBF1 levels regulate active rRNA gene chromatin during growth and differentiation.

MAD1 and c-MYC regulate UBF and rDNA transcription during granulocyte differentiation.

The regulation of cell mass (cell growth) is often tightly coupled to the cell division cycle (cell proliferation). Ribosome biogenesis and the control of rDNA transcription through RNA polymerase I are known to be critical determinants of cell growth. Here we show that granulocytic cells deficient in the c-MYC antagonist MAD1 display increased cell volume, rDNA transcription and protein synthesis. MAD1 repressed and c-MYC activated rDNA transcription in nuclear run-on assays. Repression of rDNA transcription by MAD1 was associated with its ability to interact directly with the promoter of upstream binding factor (UBF), an rDNA regulatory factor. Conversely, c-MYC activated transcription from the UBF promoter. Using siRNA, UBF was shown to be required for c-MYC-induced rDNA transcription. These data demonstrate that MAD1 and c-MYC reciprocally regulate rDNA transcription, providing a mechanism for coordination of ribosome biogenesis and cell growth under conditions of sustained growth inhibition such as granulocyte differentiation.

mTOR-dependent regulation of ribosomal gene transcription requires S6K1 and is mediated by phosphorylation of the carboxy-terminal activation domain of the nucleolar transcription factor UBF.

Mammalian target of rapamycin (mTOR) is a key regulator of cell growth acting via two independent targets, ribosomal protein S6 kinase 1 (S6K1) and 4EBP1. While each is known to regulate translational efficiency, the mechanism by which they control cell growth remains unclear. In addition to increased initiation of translation, the accelerated synthesis and accumulation of ribosomes are fundamental for efficient cell growth and proliferation. Using the mTOR inhibitor rapamycin, we show that mTOR is required for the rapid and sustained serum-induced activation of 45S ribosomal gene transcription (rDNA transcription), a major rate-limiting step in ribosome biogenesis and cellular growth. Expression of a constitutively active, rapamycin-insensitive mutant of S6K1 stimulated rDNA transcription in the absence of serum and rescued rapamycin repression of rDNA transcription. Moreover, overexpression of a dominant-negative S6K1 mutant repressed transcription in exponentially growing NIH 3T3 cells. Rapamycin treatment led to a rapid dephosphorylation of the carboxy-terminal activation domain of the rDNA transcription factor, UBF, which significantly reduced its ability to associate with the basal rDNA transcription factor SL-1. Rapamycin-mediated repression of rDNA transcription was rescued by purified recombinant phosphorylated UBF and endogenous UBF from exponentially growing NIH 3T3 cells but not by hypophosphorylated UBF from cells treated with rapamycin or dephosphorylated recombinant UBF. Thus, mTOR plays a critical role in the regulation of ribosome biogenesis via a mechanism that requires S6K1 activation and phosphorylation of UBF.