Association between in vivo fluorine 18-labeled flutemetamol amyloid positron emission tomography imaging and in vivo cerebral cortical histopathology

OBJECTIVE

To determine the correspondence of in vivo quantitative estimates of brain uptake of fluorine 18-labeled flutemetamol with immunohistochemical estimates of amyloid levels in patients who underwent previous biopsy.

DESIGN

Cross-sectional study of ¹⁸F-flutemetamol positron emission tomography (PET) findings in patients with prior cortical biopsy specimen stained for the presence or absence of amyloid plaques.

SETTING

University hospital. Patients Seven patients who previously had a prior right frontal cortical biopsy at the site of ventriculoperitoneal placement for presumed normal pressure hydrocephalus were recruited. Inclusion criteria included an adequate biopsy specimen for detection and quantification of β-amyloid pathology and age older than 50 years. Intervention All patients underwent an ¹⁸F-flutemetamol PET scan.

MAIN OUTCOME MEASURES

Quantitative measures of ¹⁸F-flutemetamol uptake (standardized uptake value ratio, a ratio of mean target cortex activity divided by that in a cerebellar reference region) were made at a location contralateral to the biopsy site and compared with estimates of amyloid load based on immunohistochemical and histological staining.

RESULTS

There was complete agreement between visual reads of ¹⁸F-flutemetamol PET scans (3 blinded readers with majority rule) and histology. A regression model, including time from biopsy as a covariate, demonstrated a significant relationship (P = .01) between ¹⁸F-flutemetamol uptake and percentage of area of amyloid measured by a monoclonal antibody raised against amyloid (NAB228). Similar results were found with the amyloid-specific monoclonal antibody 4G8 and Thioflavin S.

CONCLUSION

To our knowledge, these data are the first to demonstrate the concordance of ¹⁸F-flutemetamol PET imaging with histopathology, supporting its sensitivity to detect amyloid and potential use in the study and detection of Alzheimer disease.

18F-flutemetamol amyloid imaging in Alzheimer disease and mild cognitive impairment: a phase 2 trial

OBJECTIVE

The most widely studied positron emission tomography ligand for in vivo beta-amyloid imaging is (11)C-Pittsburgh compound B ((11)C-PIB). Its availability, however, is limited by the need for an on-site cyclotron. Validation of the (18)F-labeled PIB derivative (18)F-flutemetamol could significantly enhance access to this novel technology.

METHODS

Twenty-seven patients with early-stage clinically probable Alzheimer disease (AD), 20 with amnestic mild cognitive impairment (MCI), and 15 cognitively intact healthy volunteers (HVs) above and 10 HVs below 55 years of age participated. The primary endpoint was the efficacy of blinded visual assessments of (18)F-flutemetamol scans in assigning subjects to a raised versus normal uptake category, with clinical diagnosis as the standard of truth (SOT). As secondary objectives, we determined the correlation between the regional standardized uptake value ratios (SUVRs) for (18)F-flutemetamol and its parent molecule (11)C-PIB in 20 of the AD subjects and 20 of the MCI patients. We also determined test-retest variability of (18)F-flutemetamol SUVRs in 5 of the AD subjects.

RESULTS

Blinded visual assessments of (18)F-flutemetamol scans assigned 25 of 27 scans from AD subjects and 1 of 15 scans from the elderly HVs to the raised category, corresponding to a sensitivity of 93.1% and a specificity of 93.3% against the SOT. Correlation coefficients between cortical (18)F-flutemetamol SUVRs and (11)C-PIB SUVRs ranged from 0.89 to 0.92. Test-retest variabilities of regional SUVRs were 1 to 4%.

INTERPRETATION

(18)F-Flutemetamol performs similarly to the (11)C-PIB parent molecule within the same subjects and provides high test-retest replicability and potentially much wider accessibility for clinical and research use.

Regional survey of tuberculosis risk assessment in rheumatology outpatients commencing anti-TNF-alpha treatment in relation to British Thoracic Society guidelines

The aim of this study was to analyse tuberculosis (TB) risk assessment for rheumatology patients commencing anti-tumour necrosis factor-alpha (anti-TNF-alpha) therapy using the British Thoracic Society (BTS) guidelines. Data were obtained retrospectively on 856 outpatients regionally receiving anti-TNF-alpha. Prior to commencing treatment, patients had the following assessments documented: respiratory examination, 47.4%; chest X-ray, 84.5%; TB history, 92.9%; and advice about TB risk, 45.8%. Of the 856 patients, 94.3% were on immunosuppressives but 27% had a tuberculin test; 12.6% had > or =1 high-risk factors for TB. In total, 3.4% were referred to a TB specialist and of these, 24.1% had no risk factors for TB. Of patients with > or =1 risk factor, 76.9% were not referred. Only 4/28 patients at high risk for TB due to ethnicity or birthplace received chemoprophylaxis. Marked inter-unit variation was demonstrated and it was evident that patients require improved screening for TB. Greater awareness is necessary of patients with risk factors, particularly ethnicity, to facilitate more appropriate targeting of chemoprophylaxis. Multi-centre audit is a valuable clinical governance tool.

Selecting sanitation systems for sustainability in developing countries

This paper presents a methodology for systematically incorporating multi-dimensional sustainability considerations into the selection of wastewater options for developing countries and the evaluation and comparison of these options. Appropriate technologies for developing countries were screened based on their function and their use of operational sustainability features; this list of technologies can then be used to elaborate design options. Sustainability indicators are used to enable a parallel comparison of the options from environmental, economic, and socio-cultural perspectives. For illustration, the indicator approach is applied to a case study of the sanitation options for peri-urban/rural areas of the eThekwini Municipality in South Africa.

Experience with highly purified porcine factor VIII in a patient with haemophilia A and a factor VIII inhibitor

Highly purified porcine factor VIII has been advocated for the treatment of bleeding episodes in patients with haemophilia who have inhibitors to factor VIII. This approach has been successful in a patient with an intermediate potency inhibitor showing little cross-reactivity to porcine material. As in some other reported cases, a severe allergic reaction occurred on one occasion but did not preclude the subsequent use of the porcine concentrate in carefully controlled conditions.

Challenges with up-scaling dry sanitation technologies

The acceleration of sanitation delivery towards meeting the South African Government's target of completely eradicating the existing backlogs by 2010, has led to a surge of activities. As part of its strategy for ensuring that basic sanitation is provided, the policy has recommended that a ventilated improved pit latrine (VIP) is considered as the basic minimum requirement in the form of a sanitation technology. The up-scaling and delivering of sanitation in many cases in the form of VIPs and its derivatives, as well as urine diversion technology are beginning to pose many technical challenges. The principles on which they have been designed are not always being observed in practice. As a result, some systems are filling up much faster than expected. Research has found that the breakdown in the faeces is not happening as would be expected in an anaerobic reactor, and that the drying of faeces in humid conditions, even with the use of drying agents, is not optimum. These problems, which are being experienced in the field, will have long term repercussions on the sustainability of sanitation provision. This paper aims to share these experiences and findings of research, and the impact it may have on the Sanitation MDG goals.

Etanercept: effective in the management of hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic suppurative condition which is poorly responsive to treatment and is characterized by significant morbidity. Successful treatment of HS in patients treated with infliximab for concomitant Crohn's disease has been reported. More recent reports of positive responses to infliximab [an antitumour necrosis factor (TNF)-alpha agent] in patients who have HS but not Crohn's disease are encouraging.

OBJECTIVES

TNF-alpha is implicated in many inflammatory disorders and we wished to determine the efficacy of subcutaneous etanercept, a competitive inhibitor of TNF-alpha in the control of HS symptoms.

METHODS

We commenced six patients with severe, recalcitrant HS on etanercept (25 mg subcutaneously twice weekly in all cases). All patients had a normal chest X-ray and negative purified protein derivative test prior to treatment and were closely monitored throughout the treatment period for signs of infection. Patients self-assessed their disease activity and completed Dermatology Life Quality Index (DLQI) questionnaires immediately before the introduction of therapy and 24 weeks later in the case of four patients, and 12 weeks later in the case of two others. All patients were asked to estimate the time lapse between commencement of treatment and initial response.

RESULTS

Treatment was well tolerated by all patients with no reported adverse reactions. A marked reduction in self-reported disease activity (mean reduction of 61% at 24 weeks), in DLQI scores (mean reduction of 64% at 24 weeks) and in relapse rates occurred. All patients rated etanercept as their most effective treatment to date.

CONCLUSIONS

Our results show the effectiveness of etanercept in this group of patients with particularly challenging disease. Etanercept, unlike infliximab, may be administered subcutaneously, rendering costly day-case admissions unnecessary.

Mutation analysis in Irish families with glomuvenous malformations

BACKGROUND

Glomuvenous malformations (GVMs) are rare bluish lesions that can affect the skin and mucosal surfaces. They represent defects in vasculogenesis. Lesions can occur sporadically or in an autosomal dominant mode of inheritance. Recent studies have shown that mutations in the glomulin gene (GLMN) on chromosome 1p21-22 are responsible for familial GVMs.

OBJECTIVES

To search for mutations in GLMN in Irish families with GVMs.

METHODS

We identified four Irish families with GVMs and confirmed linkage to chromosome 1p21-22 in these cases. We sequenced the glomulin gene in all affected and unaffected members of the families. Results Linkage analysis showed that affected individuals from the families shared a common haplotype. Mutation analysis revealed a delAAGAA mutation in exon 3 of the glomulin gene in all four families with GVMs.

CONCLUSIONS

We confirm that mutations in the glomulin gene are responsible for GVMs and suggest a founder Irish mutation in the glomulin gene in four Irish families.

CD molecules 2005: human cell differentiation molecules

The immune system works through leukocytes interacting with each other, with other cells, with tissue matrices, with infectious agents, and with other antigens. These interactions are mediated by cell-surface glycoproteins and glycolipids. Antibodies against these leukocyte molecules have provided powerful tools for analysis of their structure, function, and distribution. Antibodies have been used widely in hematology, immunology, and pathology, and in research, diagnosis, and therapy. The associated CD nomenclature is commonly used when referring to leukocyte surface molecules and antibodies against them. It provides an essential classification for diagnostic and therapeutic purposes. The most recent (8th) Workshop and Conference on Human Leukocyte Differentiation Antigens (HLDA), held in Adelaide, Australia, in December 2004, allocated 95 new CD designations and made radical changes to its aims and future operational strategy in order to maintain its relevance to modern human biology and clinical practice.

Bayesian variable selection in multinomial probit models to identify molecular signatures of disease stage

Here we focus on discrimination problems where the number of predictors substantially exceeds the sample size and we propose a Bayesian variable selection approach to multinomial probit models. Our method makes use of mixture priors and Markov chain Monte Carlo techniques to select sets of variables that differ among the classes. We apply our methodology to a problem in functional genomics using gene expression profiling data. The aim of the analysis is to identify molecular signatures that characterize two different stages of rheumatoid arthritis.