Biological, clinical and population relevance of 95 loci for blood lipids

Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD.

An investigation of patients' motivations for their participation in genetics-related research

DESIGN

Qualitative interview study.

PARTICIPANTS

Fifty-nine patients with a family history of cancer who attend a regional cancer genetics clinic in the UK were interviewed about their current and previous research experiences.

FINDINGS

Interviewees gave a range of explanations for research participation. These were categorised as (a) social--research participation benefits the wider society by progressing science and improving treatment for everyone; (b) familial--research participation may improve healthcare and benefit current or future generations of the participant's family; and (c) personal--research participation provides therapeutic or non-therapeutic benefits for oneself.

CONCLUSIONS

We discuss the distinction drawn between motives for research participation focused upon self (personal) and others (familial/social), and observe that personal, social and familial motives can be seen as interdependent. For example, research participation that is undertaken to benefit others, particularly relatives, may also offer a number of personal benefits for self, such as enabling participants to feel that they have discharged their social or familial obligations. We argue for the need to move away from simple, static, individualised notions of research participation to a more complex, dynamic and inherently social account.

Genome-wide association scan meta-analysis identifies three Loci influencing adiposity and fat distribution

To identify genetic loci influencing central obesity and fat distribution, we performed a meta-analysis of 16 genome-wide association studies (GWAS, N = 38,580) informative for adult waist circumference (WC) and waist-hip ratio (WHR). We selected 26 SNPs for follow-up, for which the evidence of association with measures of central adiposity (WC and/or WHR) was strong and disproportionate to that for overall adiposity or height. Follow-up studies in a maximum of 70,689 individuals identified two loci strongly associated with measures of central adiposity; these map near TFAP2B (WC, P = 1.9x10(-11)) and MSRA (WC, P = 8.9x10(-9)). A third locus, near LYPLAL1, was associated with WHR in women only (P = 2.6x10(-8)). The variants near TFAP2B appear to influence central adiposity through an effect on overall obesity/fat-mass, whereas LYPLAL1 displays a strong female-only association with fat distribution. By focusing on anthropometric measures of central obesity and fat distribution, we have identified three loci implicated in the regulation of human adiposity.

Healthcare professionals' and researchers' understanding of cancer genetics activities: a qualitative interview study

AIMS

To describe individuals' perceptions of the activities that take place within the cancer genetics clinic, the relationships between these activities and how these relationships are sustained.

DESIGN

Qualitative interview study.

PARTICIPANTS

Forty individuals involved in carrying out cancer genetics research in either a clinical (n = 28) or research-only (n = 12) capacity in the UK.

FINDINGS

Interviewees perceive research and clinical practice in the subspecialty of cancer genetics as interdependent. The boundary between research and clinical practice is described as vague or blurred, and this ambiguity is regarded as being sustained by a range of methodological, ethical and economic factors. The implications of these findings for the "therapeutic misconception" are explored. It is argued that while research participation is seen as having therapeutic benefit for individual patients, the interviewees are not labouring under any misconceptions about the relationship between research and clinical care. It is suggested that concepts such as the "therapeutic misconception" may have less relevance in highly technological specialities that are characterised by a developing evidence base.

Common variants at 30 loci contribute to polygenic dyslipidemia

Blood low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and triglyceride levels are risk factors for cardiovascular disease. To dissect the polygenic basis of these traits, we conducted genome-wide association screens in 19,840 individuals and replication in up to 20,623 individuals. We identified 30 distinct loci associated with lipoprotein concentrations (each with P < 5 x 10(-8)), including 11 loci that reached genome-wide significance for the first time. The 11 newly defined loci include common variants associated with LDL cholesterol near ABCG8, MAFB, HNF1A and TIMD4; with HDL cholesterol near ANGPTL4, FADS1-FADS2-FADS3, HNF4A, LCAT, PLTP and TTC39B; and with triglycerides near AMAC1L2, FADS1-FADS2-FADS3 and PLTP. The proportion of individuals exceeding clinical cut points for high LDL cholesterol, low HDL cholesterol and high triglycerides varied according to an allelic dosage score (P < 10(-15) for each trend). These results suggest that the cumulative effect of multiple common variants contributes to polygenic dyslipidemia.

Direct measurements of Ab and Ac using vertex and kaon charge tags at the SLAC detector

Exploiting the manipulation of the SLAC Linear Collider electron-beam polarization, we present precise direct measurements of the parity-violation parameters A(c) and A(b) in the Z-boson-c-quark and Z-boson-b-quark coupling. Quark-antiquark discrimination is accomplished via a unique algorithm that takes advantage of the precise SLAC Large Detector charge coupled device vertex detector, employing the net charge of displaced vertices as well as the charge of kaons that emanate from those vertices. From the 1996-1998 sample of 400 000 Z decays, produced with an average beam polarization of 73.4%, we find A(c)=0.673+/-0.029(stat)+/-0.023(syst) and A(b)=0.919+/-0.018(stat)+/-0.017(syst).

Improved direct measurement of the parity-violation parameter Ab using a mass tag and momentum-weighted track charge

We present an improved direct measurement of the parity-violation parameter A(b) in the Z boson-b-quark coupling using a self-calibrating track-charge technique applied to a sample enriched in Z-->bb events via the topological reconstruction of the B hadron mass. Manipulation of the Stanford Linear Collider electron-beam polarization permits the measurement of A(b) to be made independently of other Z-pole coupling parameters. From the 1996-1998 sample of 400,000 hadronic Z decays, produced with an average beam polarization of 73.4%, we find A(b)=0.906+/-0.022(stat)+/-0.023(syst).

Improved direct measurement of A(b) and A(c) at the Z(0) pole using a lepton tag

The parity violation parameters A(b) and A(c) of the Zb(b) and Zc(c) couplings have been measured directly, using the polar angle dependence of the polarized cross sections at the Z(0) pole. Bottom and charmed hadrons were tagged via their semileptonic decays. Both the electron and muon analyses take advantage of new multivariate techniques to increase the analyzing power. Based on the 1993-1998 SLD sample of 550,000 Z(0) decays produced with highly polarized electron beams, we measure A(b) = 0.919+/-0.030(stat)+/-0.024(syst), and A(c) = 0.583+/-0.055(stat)+/-0.055(syst).

Measuring the elastic properties of fine wire

The elastic moduli of fine wires made from MP35N and 304SS used in implantable biomedical devices are assumed to be the same as those published in the literature. However, the cold working required to manufacture the wire significantly alters the elastic moduli of the material. We describe three experiments performed on fine wire made from MP35N and 304SS. The experimentally determined Young's and shear modulus of both wire types were significantly less than the moduli reported in the literature. Young's modulus differed by as much as 26%, and the shear modulus differed by as much as 14% from reported values.

Long-term efficacy and tolerability of rizatriptan wafers in migraine

CONTEXT

Rizatriptan is a selective 5-HT1B/1D receptor agonist for the acute treatment of migraine. It is available in a unique wafer formulation that dissolves rapidly in the mouth and can be taken without liquids, thereby offering patients a very convenient way to take treatment.

OBJECTIVE

To investigate the long-term efficacy of rizatriptan 10-mg and 5-mg wafers in migraineurs.

SETTING

19 headache clinics in 5 countries.

PATIENTS

458 patients diagnosed with migraine according to International Headache Society criteria.

DESIGN

6-month, open-label, extension, which followed a double-blind, placebo-controlled study.

INTERVENTIONS

Patients were randomly assigned to 1 of 3 treatments for moderate or severe migraines: rizatriptan 10-mg wafer, rizatriptan 5-mg wafer, or "standard care" (usual migraine treatment -- eg, nonsteroidal anti-inflammatory drugs [NSAIDs], analgesics, other triptans). Patients randomized to rizatriptan were blinded to the dose.

MAIN OUTCOME MEASURES

Headache severity (none, mild, moderate, severe) and adverse events were recorded on a diary card.

RESULTS

181 patients treated 3393 attacks with rizatriptan 10-mg wafer, 191 treated 3254 attacks with rizatriptan 5-mg wafer, and 86 treated 1582 attacks with standard care. The median number of treated attacks per patient was 16 for rizatriptan 10-mg wafer, 13 for rizatriptan 5-mg wafer, and 14 for standard care. The median patient on rizatriptan 10-mg wafer reported pain relief at 2 hours (reduction of headache from moderate or severe at baseline to mild or none) in 82% of attacks, vs 73% of attacks for standard care (odds ratio [95% confidence interval] = 1.63 [1.14, 2.34], P <.01) and 72% of attacks for rizatriptan 5-mg wafer (OR [95% CI] = 1.60 [1.23, 2.08], P <.001). The median patient on rizatriptan 10-mg wafer was pain free at 2 hours in 46% of attacks, vs 30% of attacks for standard care (OR [95% CI] = 1.50 [1.06, 2.12], P <.05) and 25% of attacks for rizatriptan 5-mg wafer (OR [95% CI] = 1.93 [1.50, 2.49], P <.001). All treatments were generally well tolerated. Compared with standard care, rizatriptan 5-mg wafer was associated with fewer specific adverse events of asthenia/fatigue, back pain, nausea, pharyngeal discomfort, upper respiratory infection, and vomiting (P values <.05), and, compared with rizatriptan 10-mg wafer, fewer overall drug-related adverse events (P <.05).

CONCLUSIONS

Rizatriptan 10-mg wafer was more effective than standard care and rizatriptan 5-mg wafer for treating intermittent moderate or severe migraine attacks occurring over periods of up to 6 months. Rizatriptan wafers were well tolerated.

Improved direct measurement of leptonic coupling asymmetries with polarized Z bosons

We present final measurements of the Z boson-lepton coupling asymmetry parameters A(e), A(mu), and A(tau) with the complete sample of polarized Z bosons collected by the SLD detector at the SLAC Linear Collider. From the left-right production and decay polar angle asymmetries in leptonic Z decays we measure A(e) = 0.1544+/-0.0060, A(mu) = 0.142+/-0.015, and A(tau) = 0.136+/-0.015. Combined with our left-right asymmetry measured from hadronic decays, we find A(e) = 0.1516+/-0.0021. Assuming lepton universality, we obtain a combined effective weak mixing angle of sin (2)theta(eff)(W) = 0.230 98+/-0.000 26.

First symmetry tests in polarized Z0 decays to bbg

We have made the first direct symmetry tests in the decays of polarized Z0 bosons into fully identified bbg states, collected in the SLD experiment at SLAC. We searched for evidence of parity violation at the bbg vertex by studying the asymmetries in the b-quark polar- and azimuthal-angle distributions, and for evidence of T-odd, CP-even or CP-odd, final-state interactions by measuring angular correlations between the three-jet plane and the Z0 polarization. We found results consistent with standard model expectations and set 95% C. limits on anomalous contributions.

High-precision measurement of the left-right Z Boson cross-section asymmetry

We present a measurement of the left-right cross-section asymmetry ( A(LR)) for Z boson production by e(+)e(-) collisions. The measurement includes the final data taken with the SLD detector at the SLAC Linear Collider during the period 1996-1998. Using a sample of 383 487 Z decays collected during the 1996-1998 runs we measure the pole value of the asymmetry, A(0)(LR), to be 0.150 56+/-0.002 39 which is equivalent to an effective weak mixing angle of sin (2)straight theta(eff)(W) = 0.231 07+/-0.000 30. Our result for the complete 1992-1998 data set comprising approximately 537 000 Z decays is sin (2)straight theta(eff)(W) = 0.230 97+/-0.000 27.

Development and clinical assessment of an artificial cornea

Keratoprosthesis research has been a gradual, rather fragmentary process with advances being made by isolated groups of researchers. This has arisen partly because of poor funding in the area; research groups which have achieved commercial support have often had constraints upon the full disclosure of their findings. Despite these difficulties there has been real progress over the last decade by several independent groups. This article concentrates upon our own development of a hydrogel core-and-skirt keratoprosthesis, the Chirila KPro, in order to illustrate the scientific and clinical problems common to keratoprosthesis research. Pilot data from a clinical trial is presented and the priorities for future research are discussed.