Scoring sacroiliac joints by magnetic resonance imaging. A multiple-reader reliability experiment

Magnetic resonance imaging (MRI) of the sacroiliac (SI) joints and the spine is increasingly important in the assessment of inflammatory activity and structural damage in clinical trials with patients with ankylosing spondylitis (AS). We investigated inter-reader reliability and sensitivity to change of several scoring systems to assess disease activity and change in disease activity in patients with AS. Twenty sets of consecutive MRI, derived from a randomized clinical trial comparing an active drug with placebo and selected on the basis of the presence of activity at baseline, were presented electronically to 7 experienced readers from different countries (Europe, Canada). Readers scored the MRI by 3 different methods including: a global score (grading activity per SI joint); a more comprehensive global score (grading activity per SI joint per quadrant); and a detailed scoring system [Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system], which scores 6 images, divided into quadrants, with additional scores for "depth" and "intensity." A fourth and a fifth scoring system were constructed afterwards. The fourth method included the SPARCC score minus the additional scores for "depth" and "intensity," and the fifth method included the SPARCC slice with the maximum score. Inter-reader reliability was investigated by calculating intraclass correlation coefficients (ICC) for all readers together and for all possible reader pairs. Sensitivity to change was investigated by calculating standardized response means (SRM) on change scores that were made positive. Overall inter-reader ICC per method were between 0.47 and 0.58 for scoring status, and between 0.40 and 0.53 for scoring change. ICC per possible reader pairs showed much more fluctuation per method, with lowest observed values close to zero (no agreement) and highest observed values over 0.80 (excellent agreement). In general, agreement of status scores was somewhat better than agreement of change scores, and agreement of the comprehensive SPARCC scoring system was somewhat better than agreement of the more condensed systems. Sensitivity to change differed per reader, but in general was somewhat better for the comprehensive SPARCC system. This experiment under "real life," far from optimal conditions demonstrates the feasibility of scoring exercises for method comparison, provides evidence for the reliability and sensitivity to change of scoring systems to be used in assessing activity of SI joints in clinical trials, and sets the conditions for further validation research in this field.     

Correlations and agreement between delta-9-tetrahydrocannabinol (THC) in blood plasma and timeline follow-back (TLFB)-assisted self-reported use of cannabis of patients with cannabis use disorder and psychotic illness attending the CapOpus randomized clinical trial

Aims To assess correlations and agreement between timeline follow‐back (TLFB)‐assisted self‐report and blood samples for cannabis use. Design Secondary analysis of a randomized trial. Setting Copenhagen, Denmark. Participants One hundred and three patients from the CapOpus trial with cannabis use disorder and psychosis, providing 239 self‐reports of cannabis use and 88 valid blood samples. Measurements Delta‐9‐tetrahydrocannabinol (THC), 11‐hydroxy‐delta‐9‐tetrahydrocannabinol (11‐OH‐THC) and 11‐nor‐delta‐9‐tetrahydrocannabinol‐9‐carboxylic acid (THC‐COOH) detected in plasma using high‐performance liquid chromatography with tandem mass spectrometry detection. Self‐report of cannabis‐use last month by TLFB. Pearson's r, sensitivity and specificity calculated as measures of correlation or agreement. Findings Correlations were strong; r = 0.75 for number of days and r = 0.83 for number of standard joints in the preceding month when excluding outliers. Including outliers, coefficients were moderate to strong (r = 0.49). There were differences in subgroups, mainly inconsistent, depending on inclusion or exclusion of outliers. Sensitivity and specificity for TLFB detecting the presence or absence of cannabis use were 95.7% [95% confidence interval (CI) 88.0–99.1%) and 72.2% (95% CI 46.5–90.3%), respectively. Using 19 days as cut‐off on TLFB, they were 94.3% (95% CI 86.0–98.4%) and 94.4% (95% CI 72.2–99.9%), respectively. Area under the receiver operating characteristic (ROC) curve was 0.96. Conclusions Timeline follow‐back (TLFB)‐assisted self‐report of cannabis use correlates highly with plasma‐delta‐9‐tetrahydrocannabinol in patients with comorbid cannabis use disorder and psychosis. Sensitivity and specificity of timeline follow‐back appear to be optimized with 19 days as the cut‐off point. As such, timeline follow‐back may be superior to analysis of blood when going beyond 19 days of recall.     

In vivo distribution of bismuth in the mouse brain: influence of long-term survival and intracranial placement on the uptake and transport of bismuth in neuronal tissue

Bismuth is used for a multitude of industrial purposes and has partly replaced toxic heavy metals such as lead and mercury in e.g. lubricants and shotgun pellets. In medicine, bismuth-compounds have long been used to remedy gastrointestinal disorders; lately in combination with antibiotics to treat Helicobacter pylori associated peptic ulcers. An epidemic episode of bismuth-induced encephalopathy in France in the 1970s revealed the neurotoxic potential of bismuth. This incidence, involving almost 1000 patients, remains unexplained and the contribution of other factors besides bismuth has been postulated. Recently an autometallographic technique made it possible to detect bismuth in morphologically intact tissue. In the present study, autometallographicly detectable bismuth was seen throughout the brain following intraperitoneal and intracranial exposure. The neuronal staining pattern seems highly organized with some areas heavily stained and others with low or no staining. Long-term (8 months) intraperitoneal exposure led to higher bismuth uptake than short-term (2 weeks) exposure. Following both intraperitoneal and intracranial exposure, high amounts of bismuth were found in the reticular and hypothalamic nuclei, in the oculomotor and hypoglossal nuclei and in Purkinje cells. Within the central nervous system (CNS) retrograde axonal transport was seen after intracranial bismuth exposure. Axonal transport seems to influence the distribution of bismuth as the highest uptake of bismuth after intraperitoneal exposure was seen in the facial and the trigeminal motor nuclei, i.e. neurones with processes outside the blood-brain barrier, whereas these nuclei contained no bismuth following ic exposure. Ultrastructurally, accumulation of bismuth was seen in lysosomes.     

Alkaloids from Boophane disticha with affinity to the serotonin transporter in rat brain

Bulbs and leaves of Boophane disticha are used in South African traditional medicine in the treatment of anxiety. Crude extracts of the leaves have shown affinity to the SSRI site on the serotonin transporter in a radioligand binding assay. In this study, two compounds, buphanadrine and buphanamine, were isolated by bioassay-guided fractionation on VLC and preparative TLC. The structures of the compounds were determined by (1)H and (13)C NMR. Fractions were tested for affinity to the serotonin transporter in a binding assay using [(3)H]-citalopram as ligand. The IC(50) values of buphanidrine and buphanamine were 274 microM (K(i)=132 microM) and 1799 microM (K(i)=868 microM), respectively. The two alkaloids were also tested for affinity to the 5HT(1A) receptor, but only showed slight affinity.     

Alpha-1--antitrypsin in aqueous humour from patients with corneal allograft rejection

PURPOSE: To investigate the presence and concentration of alpha1-antitrypsin in aqueous humour at the time of corneal rejection and to compare results obtained from patients with reversible and irreversible rejection. METHODS: Samples of aqueous humour were obtained from 17 patients with acute corneal endothelial allograft rejection. The presence of alpha1-antitrypsin in aqueous humour was confirmed by immunoblotting and measured employing a sandwich ELISA. Total protein concentrations in aqueous humour were measured using Bradford's method. The outcome of corneal rejection episodes was determined 1 month after diagnosing corneal rejection and described as reversible or irreversible rejection. RESULTS: alpha1-antitrypsin was detected in aqueous humour. Patients with reversible rejection had significantly higher alpha1-antitrypsin concentration than patients with irreversible rejection (p = 0.044). There was no significant difference in total protein concentrations (p = 0.745), and no correlation was found between alpha1-antitrypsin and total protein concentrations (p = 0.368). CONCLUSIONS: alpha1-antitrypsin in aqueous humour seems to signal a favourable outcome of corneal rejection. The possible mechanism is discussed.     

Assessment of HIV-1 patient recruitability in the Republic of Guinea-Bissau using African versus North American hematology and biochemistry reference intervals

Hematology and biochemistry reference intervals have been derived from healthy, HIV-negative populations to guide clinical trials worldwide. However, it is less clear how such values may be applied to clinical trials involving HIV-infected individuals. We show that contradictory interpretations about patient recruitability are reached when applying African versus North American reference intervals to an HIV-1 cohort in Guinea-Bissau. These observations underscore the need to question non-African guidelines in the context of HIV intervention clinical trials in Africa.