Radiographic progression of ankylosing spondylitis after up to two years of treatment with etanercept

OBJECTIVE

To investigate the effect of etanercept therapy on radiographic progression in patients with ankylosing spondylitis (AS).

METHODS

Patients with AS who had previously participated in a 24-week randomized, double-blind, placebo-controlled trial of etanercept therapy were enrolled in a 72-week open-label extension. Radiographs of the cervical and lumbar spine from patients who received etanercept (25 mg twice weekly) for up to 96 weeks were compared with radiographs from patients in a large prevalence cohort (Outcome Assessments in Ankylosing Spondylitis International Study [OASIS]) who had not been treated with anti-tumor necrosis factor alpha (anti-TNFalpha) agents. Radiographs obtained at 2 time points up to 96 weeks apart from patients in both study populations were digitized and read by 2 independent readers who were blinded with regard to patient group and sequence. The primary end point was the 96-week change in the modified Stoke AS Spine Score (mSASSS).

RESULTS

A total of 257 patients treated with etanercept were compared with 175 unselected patients from the OASIS study. There was no significant difference in the change in the mSASSS from baseline among patients who received etanercept (mean +/- SD 0.91 +/- 2.45) versus those from the OASIS group (0.95 +/- 3.18).

CONCLUSION

Unlike other inflammatory rheumatic diseases such as rheumatoid arthritis and psoriatic arthritis, structural progression in AS seems to be independent of TNF, despite the fact that TNF is responsible for the signs and symptoms due to inflammation in this disease.

Adalimumab effectively reduces the signs and symptoms of active ankylosing spondylitis in patients with total spinal ankylosis

Objective:

To evaluate the long-term safety and efficacy of adalimumab in patients with ankylosing spondylitis (AS) and total spinal ankylosis (TSA).

Design:

Patients (n = 315) with active AS were randomised in a 2:1 ratio to receive adalimumab 40 mg every other week or placebo for 24 weeks followed by open-label adalimumab for up to 5 years. Two-year efficacy and safety data for 11 patients with investigator-defined TSA were evaluated. The primary end point was the ASsessment in AS International Working Group criteria for 20% improvement (ASAS20) at Week 12. On or after Week 12, ASAS20 non-responders could switch to open-label adalimumab. Other efficacy measurements included ASAS40, ASAS 5/6, ASAS partial remission, and 50% improvement in the Bath AS Disease Activity Index (BASDAI 50).

Results:

6 of 11 TSA patients were randomised to adalimumab and 5 to placebo. At Week 12, 50% of the adalimumab-treated patients achieved an ASAS20 response and 33% achieved an ASAS40, ASAS 5/6 and BASDAI 50. No placebo-treated patients achieved any response criteria at Week 12. 4 placebo- and 2 adalimumab-treated patients switched to open-label adalimumab before Week 24. After 1 year of adalimumab treatment, 8 of 11 patients achieved an ASAS20 response. After 2 years, 6 of the remaining 8 patients with TSA reported an ASAS20 response. There were no serious adverse events or adverse event-related study discontinuations.

Conclusion:

In patients with TSA, adalimumab treatment resulted in rapid and clinically significant improvement in the signs and symptoms of active disease. Adalimumab effectiveness and safety were sustained for at least 2 years.

Trial registration number:

NCT00085644.

Clinical, radiographic and functional differences between juvenile-onset and adult-onset ankylosing spondylitis: results from the PSOAS cohort

AIMS

Previous data suggests that patients with juvenile-onset ankylosing spondylitis (JoAS) have more severe disease and worse functional outcomes than adult-onset AS (AoAS). The purpose of this study was to evaluate clinical, functional and radiographic differences between patients with JoAS and AoAS in a large cohort of patients with long-standing disease.

METHODS

A total of 402 subjects who met the Modified New York Criteria for definitive AS and had had disease >or=20 years were enrolled in a multi-centre cross-sectional study (Prospective Study of Outcomes in Ankylosing Spondylitis; PSOAS). JoAS was defined as initial symptoms <or=16 years of age. A total of 79 subjects with JoAS and 323 subjects with AoAS were identified. An analysis of clinical and demographic comparisons between the two groups was performed including HLA B27 status. Functional outcomes were assessed by Bath AS Functional Index (BASFI) and the Health Assessment Questionnaire modified for the Spondyloarthropathies (HAQS). Radiographic disease severity was assessed by the Bath AS Radiology Index (BASRI).

RESULTS

With the exception of obvious differences in age at onset and disease duration, demographic and clinical characteristics were similar between the two groups. However, the JoAS group trended towards more women (32.9 vs 22.9%, p = 0.07). Controlling for multiple covariates including disease duration, both the BASRI hip score and the need for total hip arthroplasty (THA) was higher in the JoAS group. The BASRI spine score (including total, lumbar and cervical spine) was significantly lower in the patients with JoAS even after controlling for multiple covariates including disease duration and gender. No difference in function (BASFI or HAQS scores) between groups was identified.

CONCLUSIONS

Compared to AoAS, subjects with JoAS have (1) less severe axial involvement radiographically, (2) similar functional outcomes, (3) more hip involvement with a greater need for THA, and (4) a slightly higher proportion of women.

An Intrinsic Bond-Centered Electronic Glass with Unidirectional Domains in Underdoped Cuprates

Removing electrons from the CuO2 plane of cuprates alters the electronic correlations sufficiently to produce high-temperature superconductivity. Associated with these changes are spectral-weight transfers from the high-energy states of the insulator to low energies. In theory, these should be detectable as an imbalance between the tunneling rate for electron injection and extraction-a tunneling asymmetry. We introduce atomic-resolution tunneling-asymmetry imaging, finding virtually identical phenomena in two lightly hole-doped cuprates: Ca(1.88)Na(0.12)CuO(2)Cl2 and Bi2Sr2Dy(0.2)Ca(0.8)Cu2O(8+delta). Intense spatial variations in tunneling asymmetry occur primarily at the planar oxygen sites; their spatial arrangement forms a Cu-O-Cu bond-centered electronic pattern without long-range order but with 4a(0)-wide unidirectional electronic domains dispersed throughout (a(0): the Cu-O-Cu distance). The emerging picture is then of a partial hole localization within an intrinsic electronic glass evolving, at higher hole densities, into complete delocalization and highest-temperature superconductivity.

Hand dominance and bone response after a distal radial fracture: a peripheral QCT study

There are no reports on bone geometry or volumetric bone density adaptations in those who have sustained a distal radial fracture. We used peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) to quantify bone and muscle response to immobilization. We measured side-side differences in women aged > or =50 yr who had previously sustained a wrist fracture (4.0+/-3.5 mean yr since fracture). We used pQCT and DXA to measure bone in 31 women (mean age 72.4+/-9.7 yr) at the 4% and 30% sites of bilateral radii; measured grip strength and functional outcome. Initially, we compared the fractured side to intact side and did not control for hand dominance. We observed greater total area (ToA) at the distal (4%) radius on the fractured side without a significant increase in density. At the midshaft (30% site), we observed significantly less ToA and cortical bone on the fracture side. Grip strength was also significantly less on the fractured side (p<0.01). We assessed dominant side fractures and nondominant fractures separately. We observed a greater discrepancy between limbs with a nondominant side fracture, even after accounting for dominance. This cross-sectional study suggests that the bone response to a nondominant fracture may differ from a dominant fracture.

The Ground State of the Pseudogap in Cuprate Superconductors

We present studies of the electronic structure of La(2-x)BaxCuO4, a system where the superconductivity is strongly suppressed as static spin and charge orders or "stripes" develop near the doping level of x = (1/8). Using angle-resolved photoemission and scanning tunneling microscopy, we detect an energy gap at the Fermi surface with magnitude consistent with d-wave symmetry and with linear density of states, vanishing only at four nodal points, even when superconductivity disappears at x = (1/8). Thus, the nonsuperconducting, striped state at x = (1/8) is consistent with a phase-incoherent d-wave superconductor whose Cooper pairs form spin-charge-ordered structures instead of becoming superconducting.

Effects of pairing potential scattering on Fourier-transformed inelastic tunneling spectra of high-Tc cuprate superconductors with bosonic modes

Recent scanning tunneling microscopy (STM) experimentally observed strong gap inhomogeneity in Bi2Sr2CaCu2O(8+delta) (BSCCO). We argue that disorder in the pair potential underlies the gap inhomogeneity, and investigate its role in the Fourier-transformed inelastic tunneling spectra as revealed in the STM. We find that the random pair potential induces unique q-space patterns in the local density of states (LDOS) of a d-wave superconductor. We consider the effects of electron coupling to various bosonic modes and find the pattern of LDOS modulation due to coupling to the B(1g) phonon mode to be consistent with the one observed in the inelastic electron tunnneling STM experiment in BSCCO. These results suggest strong electron-lattice coupling as an essential part of the superconducting state in high-Tc materials.

Interplay of electron–lattice interactions and superconductivity in Bi2Sr2CaCu2O8+δ

Formation of electron pairs is essential to superconductivity. For conventional superconductors, tunnelling spectroscopy has established that pairing is mediated by bosonic modes (phonons); a peak in the second derivative of tunnel current d2I/dV2 corresponds to each phonon mode. For high-transition-temperature (high-T(c)) superconductivity, however, no boson mediating electron pairing has been identified. One explanation could be that electron pair formation and related electron-boson interactions are heterogeneous at the atomic scale and therefore challenging to characterize. However, with the latest advances in d2I/dV2 spectroscopy using scanning tunnelling microscopy, it has become possible to study bosonic modes directly at the atomic scale. Here we report d2I/dV2 imaging studies of the high-T(c) superconductor Bi2Sr2CaCu2O8+delta. We find intense disorder of electron-boson interaction energies at the nanometre scale, along with the expected modulations in d2I/dV2 (refs 9, 10). Changing the density of holes has minimal effects on both the average mode energies and the modulations, indicating that the bosonic modes are unrelated to electronic or magnetic structure. Instead, the modes appear to be local lattice vibrations, as substitution of 18O for 16O throughout the material reduces the average mode energy by approximately 6 per cent--the expected effect of this isotope substitution on lattice vibration frequencies. Significantly, the mode energies are always spatially anticorrelated with the superconducting pairing-gap energies, suggesting an interplay between these lattice vibration modes and the superconductivity.

Definition of disease duration in ankylosing spondylitis: reassessing the concept

The concept and definition of disease duration in patients with ankylosing spondylitis is ambiguous, and often many years pass between the onset of symptoms and diagnosis. Members of the Assessment in Ankylosing Spondylitis (ASAS) International Working Group by consensus recently recommended identifying specific components of the medical history to better define and document the concept of disease duration. These include (1) the time of onset of the first symptoms of axial manifestations (including inflammatory back pain); (2) the time of onset of the first symptoms of each individual manifestation, which may be an extra-axial sign or symptom of ankylosing spondylitis, such as peripheral arthritis and enthesitis; (3) the time of onset of associated diseases belonging to the spondyloarthritides, in particular acute anterior uveitis, inflammatory bowel disease and psoriasis; and (4) the time since actual diagnosis by a healthcare provider. Such uniformity in data collection will ensure comparability across studies and facilitate future research.

Community-dwelling seniors who present to the emergency department with a fall do not receive Guideline care and their fall risk profile worsens significantly: a 6-month prospective study

INTRODUCTION

Fall risk is a major contributor to fracture risk; implementing fall reduction programmes remains a challenge for health professionals and policy-makers.

MATERIALS AND METHODS

We aimed to (1) ascertain whether the care received by 54 older adults after an emergency department (ED) fall presentation met internationally recommended 'Guideline Care', and (2) prospectively evaluate this cohort's 6-month change in fall risk profile. Participants were men and women aged 70 years or older who were discharged back into the community after presenting to an urban university tertiary-care hospital emergency department with a fall-related complaint. American Geriatric Society (AGS) guideline care was documented by post-presentation emergency department chart examination, daily patient diary of falls submitted monthly, patient interview and physician reconciliation where needed. Both at study entry and at a 6-month followup, we measured participants physiological characteristics by Lord's Physiological Profile Assessment (PPA), functional status, balance confidence, depression, physical activity and other factors.

RESULTS

We found that only 2 of 54 (3.7%) of the fallers who presented to the ED received care consistent with AGS Guidelines. Baseline physiological fall risk scores classified the study population at a 1.7 SD higher risk than a 65-year-old comparison group, and during the 6-month followup period the mean fall-risk score increased significantly (i.e. greater risk of falls) (1.7+/-1.6 versus 2.2+/-1.6, p=0.000; 29.5% greater risk of falls). Also, functional ability [100 (15) versus 95 (25), p=0.002], balance confidence [82.5 (44.4) versus 71.3 (58.7), p=0.000] and depression [0 (2) versus 0 (3), p=0.000] all worsened over 6 months. Within 6 months of the index ED visit, five participants had suffered six fall-related fractures.

DISCUSSION

We conclude that this group of community-dwelling fallers, who presented for ED care with a clinical profile suggesting a high risk of further falls and fracture, did not receive Guideline care and worsened in their fall risk profile by 29.5%. This gap in care, at least in one centre, suggests further investigation into alternative approaches to delivering Guideline standard health service.

The post-operative analgesic efficacy and tolerability of lumiracoxib compared with placebo and naproxen after total knee or hip arthroplasty

BACKGROUND

Lumiracoxib is a novel selective cyclooxygenase-2 (COX-2) inhibitor in development for the treatment of chronic and acute pain.

METHODS

This randomized, double-blind multicentre study enrolled 180 patients (aged 18-80 years) with moderate-to-severe pain (>or=2 on a 4-point categorical scale) within 48 h of unilateral total knee or total hip arthroplasty. Patients were randomized to receive lumiracoxib 400 mg once daily (n = 60), placebo (n = 60) or naproxen 500 mg twice daily (n = 60). The study consisted of a 12-h single-dose phase followed by a multiple-dose phase (up to 96 h or until discontinuation). The primary efficacy measure was the summed (time-weighted) pain intensity difference over 0-8 h after the first dose (SPID-8).

RESULTS

Lumiracoxib and naproxen were comparable and both treatments were superior to placebo for the primary efficacy measure, SPID-8. Both treatments were generally similar and also superior to placebo for the secondary efficacy measures during both the single- and multiple-dose phases for up to 96 h. Both active treatments were well tolerated.

CONCLUSION

Lumiracoxib is an effective alternative to traditional non-selective non-steroidal anti-inflammatory drugs (NSAIDs) for the treatment of post-operative pain.

ASAS/EULAR recommendations for the management of ankylosing spondylitis

OBJECTIVE

To develop evidence based recommendations for the management of ankylosing spondylitis (AS) as a combined effort of the 'ASsessment in AS' international working group and the European League Against Rheumatism.

METHODS

Each of the 22 participants was asked to contribute up to 15 propositions describing key clinical aspects of AS management. A Delphi process was used to select 10 final propositions. A systematic literature search was then performed to obtain scientific evidence for each proposition. Outcome data for efficacy, adverse effects, and cost effectiveness were abstracted. The effect size, relative risk, number needed to treat, and incremental cost effectiveness ratio were calculated. On the basis of the search results, 10 major recommendations for the management of AS were constructed. The strength of recommendation was assessed based on the strength of the literature evidence, risk-benefit trade-off, and clinical expertise.

RESULTS

The final recommendations considered the use of non-steroidal anti-inflammatory drugs (NSAIDs) (conventional NSAIDs, coxibs, and co-prescription of gastroprotective agents), disease modifying antirheumatic drugs, treatments with biological agents, simple analgesics, local and systemic steroids, non-pharmacological treatment (including education, exercise, and physiotherapy), and surgical interventions. Three general recommendations were also included. Research evidence (categories I-IV) supported 11 interventions in the treatment of AS. Strength of recommendation varied, depending on the category of evidence and expert opinion.

CONCLUSION

Ten key recommendations for the treatment of AS were developed and assessed using a combination of research based evidence and expert consensus. Regular updating will be carried out to keep abreast of new developments in the management of AS.

Atomic-Scale Sources and Mechanism of Nanoscale Electronic Disorder in Bi2Sr2CaCu2O8+

The randomness of dopant atom distributions in cuprate high-critical temperature superconductors has long been suspected to cause nanoscale electronic disorder. In the superconductor Bi2Sr2CaCu2O8+delta, we identified populations of atomic-scale impurity states whose spatial densities follow closely those of the oxygen dopant atoms. We found that the impurity-state locations are strongly correlated with all manifestations of the nanoscale electronic disorder. This disorder occurs via an unanticipated mechanism exhibiting high-energy spectral weight shifts, with associated strong superconducting coherence peak suppression but very weak scattering of low-energy quasi-particles.

Coincidence of checkerboard charge order and antinodal state decoherence in strongly underdoped superconducting Bi2Sr2CaCu2O8 + delta)

The doping dependence of nanoscale electronic structure in superconducting Bi(2)Sr(2)CaCu(2)O(8 + delta) is studied by scanning tunneling microscopy. At all dopings, the low energy density-of-states modulations are analyzed according to a simple model of quasiparticle interference and found to be consistent with Fermi-arc superconductivity. The superconducting coherence peaks, ubiquitous in near-optimal tunneling spectra, are destroyed with strong underdoping and a new spectral type appears. Exclusively in regions exhibiting this new spectrum, we find local "checkerboard" charge ordering of high energy states, with a wave vector of Q = (+/- 2pi/4.5a(0),0); (0, +/- 2pi/4.5a(0)) +/- 15%. Surprisingly, this spatial ordering of high energy states coexists harmoniously with the low energy Bogoliubov quasiparticle states.

Type I interferon correlates with serological and clinical manifestations of SLE

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting multiple organ systems triggered by the production of autoantibodies. Previous clinical studies in humans and murine models suggest that type I interferons (IFNs) are important for the initiation and potentiation of SLE activity.

METHODS

65 consecutive patients with SLE were identified from the University of California, San Francisco Lupus Clinic with moderate-severe disease activity. 94 serological samples were collected. Type I IFN levels and the ability of plasma to induce expression of several surface markers of dendritic cell maturation were measured.

RESULTS

Type I IFN levels correlated with the presence of cutaneous manifestations, and there was a trend towards correlation with renal disease. No correlation was found between type I IFN levels and neurological disease. Type I IFN levels correlated positively with the SLEDAI score and anti-dsDNA levels and inversely with C3 levels. Interestingly, type I IFN levels were highest in African American patients. SLE plasma also induced the expression of MHC class I, CD38, and CD123 on monocytes, and was blocked by the addition of a monoclonal antibody to IFNAR1.

CONCLUSIONS

The pathogenic role of type I IFN is suggested by the induction of cell surface markers for dendritic cell maturation. The potential therapeutic utility of antibodies directed to either type I IFN or IFNAR1/IFNAR2 may be of interest in further studies.

Sustained durability and tolerability of etanercept in ankylosing spondylitis for 96 weeks

OBJECTIVE

To evaluate the continued safety and durability of clinical response in patients with ankylosing spondylitis receiving etanercept.

METHODS

277 patients who had participated in a previous randomised, double blind, placebo controlled 24 week trial were eligible to continue in this open label extension study. All patients who enrolled in the open label extension (n = 257) received subcutaneous etanercept 25 mg twice weekly for up to 72 weeks, for a combined 96 weeks of cumulative trial and open label experience. For the patients who had received etanercept for 24 weeks in the double blind trial, this represented almost 2 years of continuous etanercept treatment.

RESULTS

Patients continuing etanercept treatment had a sustained response for almost 2 years, with 74% achieving an ASsessments in Ankylosing Spondylitis 20% (ASAS 20) response after 96 weeks of etanercept treatment. Patients who had received placebo in the preceding double blind trial had similar responses, with 70% of patients attaining an ASAS 20 response after 24 weeks of etanercept treatment and 78% achieving an ASAS 20 response after 72 weeks. Improved spinal mobility was seen in both groups. Etanercept was well tolerated in patients treated for up to 96 weeks.

CONCLUSION

The subcutaneous administration of twice weekly doses of etanercept provided sustained durability of response in the improvement of signs and symptoms of ankylosing spondylitis for nearly 2 years.

Lamivudine is not effective in primary Sjögren's syndrome

BACKGROUND

Retroviral infection has been implicated in the pathogenesis of primary Sjögren's syndrome.

OBJECTIVE

To examine the efficacy of the reverse transcriptase inhibitor lamivudine in patients with this syndrome.

METHODS

16 patients with primary Sjögren's syndrome were randomised to receive either lamivudine 150 mg twice daily or placebo for three months. Measures of lacrimal and salivary function, including minor salivary gland biopsies, were obtained before and after treatment.

RESULTS

Treatment with lamivudine did not result in significant improvement in the primary outcome measure of unstimulated whole salivary flow or other secondary measures, including minor salivary gland biopsy focus scores.

CONCLUSION

Lamivudine is not effective in patients with primary Sjögren's syndrome, suggesting either that a retroviral aetiology is not present or that it may be important only in early disease.

The role of balance and agility training in fall reduction. A comprehensive review

AIM

In the elderly, falls and fall-related injuries are a major problem worldwide and the number of injuries are continuing to increase. It is well established that stability requires a well-functioning muscular-skeletal system as well as an intact balance system. The purpose of this comprehensive review of controlled trials is to examine the evidence for the value of balance and agility training in preventing falls and injuries resulting from falls in older people.

METHODS

Thirteen studies meeting our inclusion criteria have been reviewed.

RESULTS

Of these 13 studies, 6 demonstrated a significant reduction in the rate of falls.

CONCLUSIONS

The conclusion is drawn that an exercise program with a balance component in healthy community dwelling older people is likely to prevent future falls.

A ‘checkerboard’ electronic crystal state in lightly hole-doped Ca2-xNaxCuO2Cl2

The phase diagram of hole-doped copper oxides shows four different electronic phases existing at zero temperature. Familiar among these are the Mott insulator, high-transition-temperature superconductor and metallic phases. A fourth phase, of unknown identity, occurs at light doping along the zero-temperature bound of the 'pseudogap' regime. This regime is rich in peculiar electronic phenomena, prompting numerous proposals that it contains some form of hidden electronic order. Here we present low-temperature electronic structure imaging studies of a lightly hole-doped copper oxide: Ca2-xNaxCuO2Cl2. Tunnelling spectroscopy (at energies |E| > 100 meV) reveals electron extraction probabilities greatly exceeding those for injection, as anticipated for a doped Mott insulator. However, for |E| < 100 meV, the spectrum exhibits a V-shaped energy gap centred on E = 0. States within this gap undergo intense spatial modulations, with the spatial correlations of a four CuO2-unit-cell square 'checkerboard', independent of energy. Intricate atomic-scale electronic structure variations also exist within the checkerboard. These data are consistent with an unanticipated crystalline electronic state, possibly the hidden electronic order, existing in the zero-temperature pseudogap regime of Ca2-xNaxCuO2Cl2.

Lymphocyte depletion with fludarabine in patients with psoriatic arthritis: clinical and immunological effects

OBJECTIVE

To obtain preliminary information on the safety and efficacy of fludarabine in PsA and analyse its immunomodulatory effects in peripheral blood and synovial tissue.

METHODS

15 patients with active PsA who did not respond to DMARDs were randomly allocated to receive fludarabine every four weeks or placebo. Primary outcomes were the proportion of patients who met the ACR20 and the psoriatic arthritis response criteria (PsARC) at 16 weeks. Secondary outcomes were changes in tender or swollen joint counts and scores of the psoriasis area and severity index (PASI). Phenotypic analysis of peripheral blood mononuclear cells (PBMC), synovial immunohistochemistry, and functional analysis of PBMC were used to determine the immunomodulatory effects of fludarabine.

RESULTS

At 16 weeks the ACR20 criteria were met by 3/7 (43%) fludarabine treated v 0/8 placebo treated patients (p=0.08); the PsARC was achieved by 4/7 (57%) fludarabine treated v 2/8 (25%) placebo treated patients; and 3/7 (43%) fludarabine treated v 0/7 placebo treated patients had > or =20% improvement in the PASI. Marked peripheral lymphopenia involving naive (CD4(+) CD45RA(+)) and memory (CD4(+) CD45RO(+)) T cells, CD8(+) T cells, and B cells was seen in fludarabine treated patients.

CONCLUSIONS

In PsA fludarabine induces significant peripheral, but modest, synovial lymphopenia, and a trend towards improved clinical response.

Relating atomic-scale electronic phenomena to wave-like quasiparticle states in superconducting Bi2Sr2CaCu2O8+delta

The electronic structure of simple crystalline solids can be completely described in terms either of local quantum states in real space (r-space), or of wave-like states defined in momentum-space (k-space). However, in the copper oxide superconductors, neither of these descriptions alone may be sufficient. Indeed, comparisons between r-space and k-space studies of Bi2Sr2CaCu2O8+delta (Bi-2212) reveal numerous unexplained phenomena and apparent contradictions. Here, to explore these issues, we report Fourier transform studies of atomic-scale spatial modulations in the Bi-2212 density of states. When analysed as arising from quasiparticle interference, the modulations yield elements of the Fermi-surface and energy gap in agreement with photoemission experiments. The consistency of numerous sets of dispersing modulations with the quasiparticle interference model shows that no additional order parameter is required. We also explore the momentum-space structure of the unoccupied states that are inaccessible to photoemission, and find strong similarities to the structure of the occupied states. The copper oxide quasiparticles therefore apparently exhibit particle-hole mixing similar to that of conventional superconductors. Near the energy gap maximum, the modulations become intense, commensurate with the crystal, and bounded by nanometre-scale domains. Scattering of the antinodal quasiparticles is therefore strongly influenced by nanometre-scale disorder.