Complex vascular lesions at autopsy in a patient with phentermine-fenfluramine use and rapidly progressing pulmonary hypertension.

Anorectic agents, such as aminorex and fenfluramine derivatives, have been associated previously with the development of primary pulmonary hypertension. The combination diet drug phentermine-fenfluramine (or "phen-fen") was recently marketed in the United States. We describe a case of a 39-year-old woman with rapidly progressing, fatal pulmonary hypertension following administration of phentermine-fenfluramine. Autopsy was remarkable for complex pulmonary vascular lesions most consistent with thrombotic arteriopathy.     

Doppler evaluation of extracranial cerebrovascular disease.

The carotid Doppler examination is an accurate means of screening the extracranial carotid system for stenotic lesions. Comparison of 100 patients (200 vessels) examined by the Doppler method and arteriography showed agreement in 90% of the vessels and a significant error rate in only 3.5%.     

Reservoir competence of lesser mealworm (Coleoptera: Tenebrionidae) for Campylobacter jejuni (Campylobacterales: Campylobacteraceae)

The lesser mealworm, Alphitobius diaperinus (Panzer), is a carrier of Campylobacter spp. in poultry facilities; however, the beetle's importance in the epidemiology of campylobacteriosis is not known. A series of laboratory experiments were designed to test the vector and reservoir competence of the lesser mealworm for Campylobacter jejuni. In the first experiment, C. jejuni was swabbed onto the outer surface of adult and larval beetles to determine how long bacteria can survive on the beetles' exterior. Next, adult and larval mealworms were allowed to drink from a solution containing C. jejuni and the duration of internal carriage was monitored. For the third experiment, beetles drank from a Campylobacter suspension and the duration of fecal shedding of bacteria was determined. In the last experiment, 3-d-old chickens were fed either one or 10 infected beetles, and cloacal swabs were tested periodically for Campylobacter. C. jejuni was detected on the exterior of larval beetles for 12 h, from the interior of larvae for 72 h, and from the feces of larvae for 12 h after exposure. Ninety percent of the birds that consumed a single adult or larval beetles became Campylobacter-positive, whereas 100% of the birds that consumed 10 adults or larvae became positive. These experiments demonstrated that the lesser mealworm could acquire and harbor Campylobacter from an environmental source. We found that the lesser mealworm was capable of passing viable bacteria to chickens that consumed the beetle. The beetle should be included in attempts to maintain Campylobacter-free poultry facilities.     

Cold testing through full-coverage restorations

Endodontic diagnosis often requires thermal testing through porcelain fused-to-metal (PFM) and all-ceramic restorations. The purpose of this study was to measure and compare the temperature change during thermal testing by three commonly used methods occurring at the pulp-dentin junction (PDJ) of nonrestored teeth and teeth restored with full coverage restorations made of PFM, all-porcelain, or gold. The methods used to produce a thermal change were (a) an ice stick, (b) 1,1,1,2-tetrafluoroethane (TFE), and (c) carbon dioxide snow. A thermocouple measured temperature changes occurring at the PDJ in 10 extracted premolars when thermal tested by each method over a period of 30 seconds. Temperature reduction was also measured for the same samples restored with full gold crowns, PFM, and Empress crowns. Results showed intact premolars and those restored with PFM or all-ceramic restorations to respond similarly to thermal testing. In these teeth, TFE produced a significantly greater temperature decrease than carbon dioxide snow between 10 and 25 seconds (p < 0.05). In conclusion, application of TFE on a saturated #2 cotton pellet was the most effective method for producing a temperature reduction at the PDJ of intact teeth and those restored with gold, PFM, and all-porcelain when testing for less than 15 seconds.     

Optimizing the fMRI data-processing pipeline using prediction and reproducibility performance metrics: I. A preliminary group analysis

We argue that published results demonstrate that new insights into human brain function may be obscured by poor and/or limited choices in the data-processing pipeline, and review the work on performance metrics for optimizing pipelines: prediction, reproducibility, and related empirical Receiver Operating Characteristic (ROC) curve metrics. Using the NPAIRS split-half resampling framework for estimating prediction/reproducibility metrics (Strother et al., 2002), we illustrate its use by testing the relative importance of selected pipeline components (interpolation, in-plane spatial smoothing, temporal detrending, and between-subject alignment) in a group analysis of BOLD-fMRI scans from 16 subjects performing a block-design, parametric-static-force task. Large-scale brain networks were detected using a multivariate linear discriminant analysis (canonical variates analysis, CVA) that was tuned to fit the data. We found that tuning the CVA model and spatial smoothing were the most important processing parameters. Temporal detrending was essential to remove low-frequency, reproducing time trends; the number of cosine basis functions for detrending was optimized by assuming that separate epochs of baseline scans have constant, equal means, and this assumption was assessed with prediction metrics. Higher-order polynomial warps compared to affine alignment had only a minor impact on the performance metrics. We found that both prediction and reproducibility metrics were required for optimizing the pipeline and give somewhat different results. Moreover, the parameter settings of components in the pipeline interact so that the current practice of reporting the optimization of components tested in relative isolation is unlikely to lead to fully optimized processing pipelines.     

An evaluation of methods for detecting brain activations from functional neuroimages

Brain activation studies based on PET or fMRI seek to explore neuroscience questions by statistically analyzing the acquired images to produce statistical parametric images (SPIs). An increasingly wide range of univariate and multivariate analysis techniques are used to generate SPIs in order to detect mean-signal activations and/or long-range spatial interactions. However, little is known about the comparative detection performance of even simple techniques in finite data sets. Our aims are (1) to empirically compare the detection performance of a range of techniques using simulations of a simple image phantom and receiver operating characteristics (ROC) analysis, and (2) to construct two near-optimal detectors, both generalized likelihood ratio tests as upper performance bounds.We found that for finite samples of (10-100) images, even when the t-test with single-voxel variance estimates (single-voxel t-test) is the "correct" (i.e. unbiased) model for simple local additive signals, better detection performance is obtained using pooled variance estimates or adaptive, multivariate covariance-based detectors. Normalization by voxel-based variance estimates causes significantly decreased detection performance using either single-voxel t-tests or correlation-coefficient thresholding compared to pooled-variance t-tests or covariance thresholding, respectively. Moreover, we found that SVD by itself, or followed by an adaptive Fisher linear discriminant, provides a detector that is (1) more sensitive to mean differences than a single-voxel t-test, (2) insensitive to the large local signal variances detected by covariance thresholding, and (3) much more sensitive to signal correlations than correlation-coefficient thresholding. Adaptive, multivariate covariance-based approaches and pooled-variance t-tests represent promising directions for obtaining optimal signal detection in functional neuroimaging studies.     

Pulmonary cystic hydatid disease in Ireland

Background Hydatid disease is rare in Ireland and its incidence and prevalence are unknown. Most cases are diagnosed by a combination of clinical findings, morphological features on imaging and by serological testing. Aims We describe an Irish case of pulmonary hydatid disease detected at bronchoscopy by bronchoalveolar lavage, and discuss the diagnosis and treatment of the disorder.