Clinical and imaging correlates of response to treatment with infliximab in patients with ankylosing spondylitis

OBJECTIVES

Ankylosing spondylitis (AS) is a chronic disease leading to progressive spinal ankylosis and deformity. The aims of this study were to (1) determine whether infliximab is an effective treatment for AS patients who have failed conventional treatment; (2) identify any baseline clinical variables that can be associated with responsiveness to treatment; and (3) resolve whether the clinical response correlated with changes from baseline inflammatory changes on magnetic resonance imaging (MRI).

METHODS

Twenty-one patients who met the modified New York criteria for AS (M:F 18:3) were enrolled in this open labeled study. The mean age was 37.9+/-7.9 years and mean disease duration was 8.69+/-6.58 years. Patients received infliximab at a dose of 5 mg/kg by intravenous infusion over 2 hours at 0, 2, 6, weeks. Nine functional variables were measured [i.e., Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI) etc.], 6 clinimetrics (chest expansion, finger to floor, etc.), and inflammatory markers in the peripheral blood at baseline and each subsequent visit. Primary response to treatment was defined as a > 20% response in 5/9 functional variables. A subset of 9 consecutive patients was selected for MRI scans before and after infusions.

RESULTS

Eighteen patients were available for assessment at week 14 having received 3 infusions (wks 0, 2, 6). There was > 60% improvement in functional variables, i.e., BASDAI, BASFI, Health Assessment Questionnaire, fatigue, and spinal and total body pain. Clinimetric scores selectively improved, e.g., chest expansion (p < 0.021) by 14 weeks. ESR, CRP and haptoglobin all showed significant improvement at 6 weeks and were maintained to the 14 week assessment point. Imaging studies showed improvement in all patients studied including those with advanced disease. Three patients developed headache during the infusions. Infliximab was effective in all, but degree of response varied. Very good responders were distinguished from good responders by shorter duration of disease and better baseline clinimetric scores.

CONCLUSIONS

Infliximab was an effective treatment for AS in a short term trial. Longterm control of symptoms and potential alteration in clinical course of disease will require longterm assessment.

Modeling the motion of the internal tongue from tagged cine-MRI images

A new technique, tagged Cine-Magnetic Resonance Imaging (tMRI), was used to develop a mechanical model that represented local, homogeneous, internal tongue deformation during speech. The goal was to infer muscle activity within the tongue from tissue deformations seen on tMRI. Measurements were made in three sagittal slices (left, middle, right) during production of the syllable /ka/. Each slice was superimposed with a grid of tag lines, and the approximately 40 tag line intersections were tracked at 7 time-phases during the syllable. A local model, similar to a finite element analysis, represented planar stretch and shear between the consonant and vowel at 110 probed locations within the tongue. Principal strains were calculated at these locations and revealed internal compression and extension patterns from which inferences could be drawn about the activities of the Verticalis, Hyoglossus, and Superior Longitudinal muscles, among others.

Prospective memory in dynamic environments: effects of load, delay, and phonological rehearsal

A new paradigm was developed to examine prospective memory performance in a visual-spatial task that resembles some aspects of the work of air traffic controllers. Two experiments examined the role of workload (number of aeroplanes that participants directed), delay (between receipt of prospective instructions and execution), and phonological rehearsal. High workload increased prospective memory errors but increasing delay from 1-3 or 5 minutes had no effect. Shadowing aurally presented text reduced prospective memory performance, presumably because it prevented verbal rehearsal of the prospective instructions. However, performance on the foreground task of directing aeroplanes to routine destinations was affected only by workload and not by opportunity for rehearsal. Our results suggest that ability to maintain performance on a routine foreground task while performing a secondary task--perhaps analogous to conversation--does not predict ability to retrieve a prospective intention to deviate from the routine.

Cost effectiveness analysis of BMD referral for DXA using ultrasound as a selective pre-screen in a group of women with low trauma Colles' fractures

Measurements of bone density (BMD) are central to the World Health Organisation (WHO) approach to the definition of osteoporosis. Dual energy X- ray absorptiometry (DXA) remains the gold standard technique for measuring the bone mineral density (BMD) but Quantitative Ultrasound (QUS) is an attractive alternative method of bone assessment because it is easy to use and relatively inexpensive. It has been suggested that QUS could be used as a selective population pre-screen, to maximise the cost effectiveness of referral for DXA assessment of BMD. We set out to examine how such an approach might perform in the assessment of women with low trauma Colles' fracture. In 46 women aged 50-80 (mean 67) years we used DXA to measure BMD at lumbar spine and hip, and heel bone ultrasound to measure Broad Band Attenuation (BUA) and Velocity of Sound (VOS). We calculated local costs of pounds sterling 45 for DXA and pounds sterling 15 for QUS. We identified a BUA threshold of 60 dB/MHz as most cost effective as pre-screen, and calculated a sensitivity of 93% and specificity of 84% in identifying those subjects who were subsequently identified as having osteoporosis by DXA. DXA assessment of all patients had a cost of pounds sterling 77 per osteoporotic subject identified. We examined the cost-effectiveness of using QUS as a pre-screen, only referring subjects for more expensive DXA assessment if BUA was less than 60 dB/MHz. However this approach had no advantage, still costing pounds sterling 78 per osteoporotic subject identified. QUS assessment does not appear cost-effective as a pre-screen for DXA, even in this high risk group of women with low trauma Colles' fracture. A QUS pre-screen would only be cost-effective if the scan could be performed at a substantially lower cost.

Prenatal RHD gene determination and dosage analysis by PCR: clinical evaluation

BACKGROUND

Use of the polymerase chain reaction (PCR) for detection of the RHD gene can measure the RHD gene status for unborn babies at risk for hemolytic disease of the newborn (HDN). The occurrence of D gene variants has led to errors in prenatal typing. Previous reports have highlighted the danger of assigning a positive fetus as negative, resulting in intrauterine fetal deaths.

OBJECTIVE

To evaluate the effectiveness of a testing strategy whereby PCR was not only performed to determine the presence/absence of the RHD gene, but also used to assess the D gene copy number (zero, one or two RHD genes) in family studies for at risk pregnancies.

METHODS

Samples comprising maternal (57) and paternal (42) peripheral blood samples, amniotic fluid (64), and matching cord blood (64) were collected. Rhesus (Rh) serotyping was performed on all blood samples. For RHD genotyping, DNA was extracted from all samples except for 28 cord samples, where only serotyping was performed (total 199 DNA genotyping). RHD gene PCR amplified exon 4 and exon 7 regions of the RHD gene. The dosage of RHD gene was determined by comparing the intensity of the RHD gene to that of the RHCE gene.

RESULTS

A total of 197/199 samples showed concordance between exon 4 and exon 7 PCR results. Two discrepant results occurred in one family: the father carried one normal D gene and one D gene variant where PCR was tested to be positive using exon 4 but negative using exon 7. One of a pair of dizygotic twins inherited this abnormal D gene and was mildly affected by HDN. This was correctly identified antenatally and the pregnancy successfully managed. The concordance rate between serotypes and genotypes for 135 blood samples was 100%. Amongst the family groups, 8/14 heterozygous fathers transmitted the D gene and 26/26 homozygous fathers transmitted the D gene to the babies. The concordance rate between RHD genotypes from amniotic fluid and Rh D serotypes from cord blood was also 100%.

CONCLUSION

The present study demonstrates the effectiveness of using PCR in a clinical setting. It verifies the importance of testing more than one region of the gene, and also the need for a testing strategy where both maternal and paternal testing for RHD gene dosages are performed.

The role of selective attention in perceptual and affective priming

Two kinds of perceptual priming (word identification and word fragment completion), as well as preference priming (that may rely on special affective mechanisms) were examined after participants either read or named the colors of words and nonwords at study. Participants named the colors of words more slowly than the colors of nonwords, indicating that lexical processing of the words occurred at study. Nonetheless, priming on all three tests was lower after color naming than after reading, despite evidence of lexical processing during color naming shown by slower responses to words than to nonwords. These results indicate that selective attention to (rather than the mere processing of) letter string identity at study is important for subsequent repetition priming.

Low proliferative rate of invasive node-negative breast cancer predicts for a favorable outcome: a prospective evaluation of 669 patients

This study was designed to compare outcome in terms of disease-free survival (DFS) in women with histologically negative axillary lymph nodes and documented low proliferative rate cancer to other well-defined prognostic factors including type of adjuvant treatment. Between 1988 and 1998, we studied 669 patients with invasive node-negative breast cancer up to 5 cm in size and low proliferative rate measured by flow cytometry to determine S-phase fraction (SPF) or by histochemistry (Ki67/MIB1). At a median follow-up of 53 months, 5-year DFS for the entire group was 94% and did not differ significantly by type of systemic adjuvant treatment: none (133 patients, 95% DFS), tamoxifen (441 patients, 94% DFS), or chemotherapy with doxorubicin and cyclophosphamide (95 patients, 92% DFS). In a multivariate prognostic factor analysis, only tumor size was significant; 5-year DFS was 96% for T1N0 cancer versus 89% for T2N0 cancer (P = 0.01). We have prospectively confirmed that a low rate of proliferation as measured by SPF or MIB1 determination confers an excellent prognosis in invasive node-negative breast cancer up to 5 cm in size, regardless of adjuvant treatment.

Photo-induced inactivation of protein kinase calpha by dequalinium inhibits motility of murine melanoma cells

Dequalinium (DECA) is a potent antitumor agent and inhibitor of protein kinase C (PKC). Previously it was shown that PKCalpha activity in vitro could be irreversibly inhibited when treated with DECA at low micromolar concentrations and irradiated with 366 nm of light. This approach was used to probe the role of intracellular PKC activity in the motility of metastatic murine melanoma B16 F10 cells and as a target for DECA analogs with increasing PKC inhibitory potencies. Pretreatment of a monolayer of B16 F10 cells with 250 nM of a DECA analog in the presence of UV irradiation for 5 min resulted in 1) complete inhibition of cell motility for up to 4 h in a time-lapse motility assay and 40 to 60% inhibition of cell migration in a Boyden chamber, and 2) inhibition by 40 to 60% of intracellular phosphatidylserine/Ca(2+)-dependent PKC catalytic activity, signifying inactivation of a conventional PKC isoform. Because PKCalpha is the only conventional PKC isoform detected in B16 F10 cells, a stably transfected clone expressing a kinase-defective mutant of PKCalpha was developed that exhibited a substantial loss of adhesion and motility and was refractory to further inhibition by DECA. These findings identify PKCalpha catalytic activity both as a mechanistic component of cell motility and adhesion and as a critical intracellular target of DECA. These studies further suggest that the combined use of UV with nanomolar concentrations of DECA offers an effective chemotherapeutic approach to inhibit metastatic behavior of melanoma cells.

A fruiting body tissue method for efficient Agrobacterium-mediated transformation of Agaricus bisporus

We describe a modified Agrobacterium-mediated method for the efficient transformation of Agaricus bisporus. Salient features of this procedure include cocultivation of Agrobacterium and fruiting body gill tissue and use of a vector with a homologous promoter. This method offers new prospects for the genetic manipulation of this commercially important mushroom species.

Probing for genes in seronegative spondyloarthropathy

Seronegative spondyloarthropathies are a group of disorders characterized by inflammation of the spine, sacroiliac joints, and peripheral arthritis along with various characteristic extra-articular features. Their pathogenesis and immunogenetics have not yet been fully elucidated. Ankylosing Spondylitis (AS) is probably the best studied of these disease. It has now been 27 years since the association of human leukocyte antigen (HLA) B27 and AS has been demonstrated. Since then, a plethora of association studies and linkage studies unequivocally demonstrate that genetic determinants within or near the major histocompatible complex (MHC) are critical to the etiology of AS. Surprisingly though, the total MHC contribution to AS has been estimated at only 30%. In this review, we highlight the genetic basis of AS as the prototypical chronic axial arthritis, and discuss the rationale and approach in searching for non-HLA linked genes.

What proportion of patients refuse consent to data collection from their records for research purposes?

In a randomised trial of the implementation of guidelines for asthma and angina, we sent questionnaires that included a request for consent to collect data from the patient's clinical records to 5069 patients in 81 general practices. Of these 3429 (67.6%) responded, of whom 335 (9.8% [95%, CI = 8.8%-10.8%]) refused consent. We conclude that consent should always be sought unless a research ethics committee has waived this requirement for pressing reasons.

Analysis of latency in cattle after inoculation with a temperature sensitive mutant of bovine herpesvirus 1 (RLB106)

Calves were inoculated with the bovine herpes virus 1 (BHV-1) vaccine strain (RLB 106), which is a temperature sensitive mutant. The route of inoculation was intranasal instillation or intramuscular (i.m.) injection (flank or neck). As a control, five calves were given placebo by i.m. injection of the neck. Regardless of the infection route, clinical symptoms did not occur. However, BHV-1 neutralizing antibodies were detected after inoculation demonstrating that sero-conversion occurred. At 60 days post-inoculation, dexamethasone was given by i.m. injection to attempt reactivation of RLB 106. Only those calves inoculated by the intranasal route shed virus leading to an increase in BHV-1 specific antibodies. As expected, viral DNA and the latency related-RNA were detected in trigeminal ganglia (TG) of calves inoculated by the intranasal route. In contrast, viral nucleic acid was not detected in TG of calves inoculated by the i.m. route or in calves inoculated with placebo. In cervical ganglia or sacral dorsal root ganglia, viral nucleic acid was not consistently detected. This study provides evidence that efficient latency and reactivation does not occur following i.m. inoculation. Since serum-neutralizing antibodies were detected in all inoculated calves, i.m. inoculation led to sero-conversion.

Acoustic energy and momentum in a moving medium

By exploiting the mathematical analogy between the propagation of sound in a nonhomogeneous potential flow and the propagation of a scalar field in curved space-time, various wave "energy" and wave "momentum" conservation laws are established in a systematic manner. In particular, the acoustic energy conservation law due to Blokhintsev appears as the result of the conservation of a mixed covariant and contravariant energy-momentum tensor, while the exchange of relative energy between the wave and mean flow, first noted by Longuet-Higgins and Stewart in the context of ocean waves, appears as the covariant conservation of the doubly contravariant form of the same energy-momentum tensor.

Dissecting room problem: prevalence of latex allergy among medical students

Latex gloves are in widespread use among preclinical medical and dental students in the dissecting room. Increasing numbers of cases of severe latex sensitivity are being reported. This study was carried out to assess the size of this problem among preclinical and clinical students. First-year students (196) and fifth-year students (155) of the United Medical and Dental Schools of Guy's and St. Thomas's Hospitals (UMDS) were asked to complete a questionnaire about symptoms related to allergy to latex gloves and associated risk factors. The prevalence of all self-reported symptoms was 9.6% overall with no significant difference between first- and fifth-year students. The prevalence of rash was significantly different; 2.6% in first-year and 8.5% in fifth-year students. Of those who reported symptoms, there was a significant excess of females and of individuals with eczema, hay fever, or a family history of atopic conditions, compared with those without symptoms. There was no difference between racial groups and no demonstrable link with a history of food allergy, previous surgery, or sensitivity to household rubber products. Only 2 of the 29 individuals with symptoms reported for skin-prick testing, one of whom demonstrated Type I hypersensitivity.

The continuing risk of domestic hot water scalds to the elderly

Elderly people are particularly at risk of accidents in the home and with an ageing population, they constitute a large proportion of scald victims. We have seen several elderly patients every year in our own unit who had sustained domestic hot water burns. We decided to ascertain the temperature of water in the private homes of elderly people and in residential care homes in our community. Twenty-five private homes and 14 residential care homes were visited and peak water temperatures were measured in the kitchens and bathrooms. Only one private home and one residential home had water below 45 degrees C. It is recommended that water should be delivered at less than 43 degrees C. We conclude that water is dangerously hot. However, if water is stored at a temperature of less than 60 degrees C there is a risk of infection with Legionella pneumophila. Existing regulations governing the use of 'fail safe' thermostatic mixing devices must be enforced and extended to cover domestic hot water systems.

Virus-induced neuronal apoptosis blocked by the herpes simplex virus latency-associated transcript

Latent infections with periodic reactivation are a common outcome after acute infection with many viruses. The latency-associated transcript (LAT) gene is required for wild-type reactivation of herpes simplex virus (HSV). However, the underlying mechanisms remain unclear. In rabbit trigeminal ganglia, extensive apoptosis occurred with LAT(-) virus but not with LAT(+) viruses. In addition, a plasmid expressing LAT blocked apoptosis in cultured cells. Thus, LAT promotes neuronal survival after HSV-1 infection by reducing apoptosis.

Trauma in elderly people: what proportion of fractures are a consequence of bone fragility?

Epidemiologists have tended to equate osteoporotic fractures with those which occur after only moderate trauma, or which affect elderly people. We set out to critically examine this epidemiological approach, because even among elderly people some fractures will be a result of severe trauma and these cannot be assumed to reflect bone fragility. In a population based study of all Cardiff residents aged over 60 we identified everyone who presented with a fracture during 1996. We considered the events that led to each fracture, to establish which fractures were a result of 'severe' trauma: trauma greater than a fall from a standing height. We identified 1335 people who between them sustained a total of 1372 fractures. 168 (12%) of the fractures resulted from severe trauma, but in people aged over 80 only 6% of all fractures, 4% of hip fractures, and 3% of wrist fractures followed severe trauma. In older subjects severe trauma makes only a very small contribution to the causation of fracture, so that the age-sex distribution of fractures following moderate trauma closely resembles that of fractures overall. For epidemiological purposes it does appear justifiable to equate the consequences of bone fragility with the occurrence of osteoporosis associated fractures in elderly people.

Functional interaction between E-cadherin and alphav-containing integrins in carcinoma cells

We have demonstrated the possibility of cross-talk between E-cadherin and alphav integrins in breast carcinoma cells. Using the function-blocking anti-alphav monoclonal antibody 17E6, applied to monolayer cultures of breast cancer lines, it was found that treatment of cells possessing detergent-insoluble (implying attachment to the actin cytoskeleton) E-cadherin resulted in the adoption of a spheroid configuration of cell growth. This effect was dependent upon not just alphav occupancy but also receptor aggregation. Thus in vitro alphav-dependent adhesion suppresses E-cadherin-mediated morphological changes. To investigate whether manipulation of E-cadherin would, conversely, modulate integrin activity we introduced a dominant-negative E-cadherin construct into one of the lines, ZR75-1, giving rise to the cell line ZR-E2R1. Surface expression of endogenous E-cadherin was downregulated (by around 25%), whereas beta-catenin levels were increased two- to threefold in ZR-E2R1 cells. There was also a highly significant increase in migration of ZR-E2R1 cells (relative to control cells) toward vitronectin (P&lt;0.001), but not toward collagen type I, fibronectin or laminin. Such increased migration could be abrogated totally by antibody blockade of alphavbeta5 and alphavbeta1 integrins. There was no detectable change in alphav integrin levels. These data suggest that the introduction of a dominant-negative E-cadherin mutant into ZR75-1, in addition to a loss of cohesion, generates a signal (or signals) which increases migration towards vitronectin through increased activity of alphav integrins.

Minimum requirements for remote realtime fetal tele-ultrasound consultation

We studied the transmission bandwidth required for accurate diagnoses when performing realtime fetal tele-ultrasound consultations. The study was divided into three phases. In phase I, three experienced clinicians evaluated the quality of ultrasound images transmitted at various bandwidths (internally looped back within Brisbane) using eight commercially available codecs at random. The two codecs that performed best proceeded to phase 2, in which a realtime video-link of up to 2 Mbit/s was set up between Brisbane and Townsville (1,500 km apart). Testing with a standard video-tape was performed at seven different bandwidths selected at random, with four clinicians (who were blinded to the equipment and bandwidths used). The optimum line rates for transmission were determined, and testing was then performed using these line rates for fetuses with various anomalies (phase 3). The results showed significant differences in performance according to bandwidths used, but not according to observers. Bandwidths were grouped into three levels. At level I (256 kbit/s) the performance was significantly worse than at level II (384, 512 or 768 kbit/s), which was in turn worse than that at level III (1, 1.5 or 2 Mbit/s). However, within each level, performance at one bandwidth was not significantly different from that at the others. The most cost-effective transmission rates therefore appeared to be 384 kbit/s and 1 Mbit/s. Further testing with fetuses affected by various anomalies confirmed that the majority could be diagnosed using a 384 kbit/s link, with slight improvement in evaluation when the bandwidth was increased to 1 Mbit/s.

The latency-related gene of bovine herpesvirus 1 inhibits programmed cell death

Although viral gene expression occurs in the peripheral nervous system during acute infection, bovine herpesvirus 1 (BHV-1) gene expression is extinguished, many neurons survive, and latency ensues. The only abundant viral transcript expressed during latency is the latency-related (LR) RNA, which is alternatively spliced in trigeminal ganglia during acute infection (L. Devireddy and C. Jones, J. Virol. 72:7294-7301, 1998). A subset of neurons express a protein encoded by the LR gene and the LR protein (LRP) is associated with cyclin-dependent kinase 2 (Cdk2)/cyclin complexes during productive infection (Y. Jiang, A. Hossain, M. T. Winkler, T. Holt, A. Doster, and C. Jones, J. Virol. 72:8133-8142, 1998). LR gene products inhibit cell cycle progression, perhaps as a result of LRP interacting with Cdk2/cyclin complexes. During acute infection, expression of cyclin A occurs in trigeminal ganglionic neurons (L. M. Schang, A. Hossain, and C. Jones, J. Virol. 70:3807-3814, 1996). Inappropriate expression of G(1)- and S-phase cyclins can initiate programmed cell death (PCD), apoptosis, in neurons, suggesting that LR gene products inhibit PCD. To test this hypothesis, we modified an assay to measure PCD frequency in transiently transfected cells. C(6)-ceramide, fumonisin B(1) (FB(1)), or etoposide was used to initiate PCD following transfection of cells with plasmids expressing LR gene products and the beta-galactosidase gene. Transfected cells that survived were quantified by counting beta-galactosidase-positive cells. Plasmids that expressed LR gene products promoted survival of monkey kidney (CV-1), human lung (IMR-90), or mouse neuroblastoma (neuro-2A) cells after induction of PCD. Plasmids with termination codons at the beginning of LR open reading frames or deletion of sequences that mediate splicing of LR RNA did not promote cell survival following PCD induction. We hypothesize that LR gene products play a role in promoting survival of postmitotic neurons during acute infection or reactivation.

Convergent behavioral and neuropsychological evidence for a distinction between identification and production forms of repetition priming

Four experiments examined a distinction between kinds of repetition priming which involve either the identification of the form or meaning of a stimulus or the production of a response on the basis of a cue. Patients with Alzheimer's disease had intact priming on picture-naming and category-exemplar identification tasks and impaired priming on word-stem completion and category-exemplar production tasks. Division of study-phase attention in healthy participants reduced priming on word-stem completion and category-exemplar production tasks but not on picture-naming and category-exemplar identification tasks. The parallel dissociations in normal and abnormal memory cannot be explained by implicit-explicit or perceptual-conceptual distinctions but are explained by an identification-production distinction. There may be separable cognitive and neural bases for implicit modulation of identification and production forms of knowledge.