Immunological assessment of exposure to Echinococcus granulosus in a rural dog population in Uruguay.

An ELISA was used to screen a dog population in Uruguay (Sarandi Del Yi, Durazno District) for the prevalence of specific serum antibodies (IgG, IgA and IgE) to Echinococcus granulosus. The sensitivity (61%) and specificity (97%) of the ELISA were determined using well-defined serum groups. A total of 408 dogs from Sarandi del Yi and environs were screened serologically, and 29.7% (8.6-13.8% for each antibody class) of dogs had positive levels of antibody to E. granulosus. This antibody prevalence (exposure) was significantly higher than the percentage of dogs found to be positive for E. granulosus worms by arecoline purgation (7.6%). This level of exposure to E. granulosus determined by ELISA is considered unacceptable from a public health perspective. Measures will now focus on obtaining data on the true prevalence of current infection in this dog population and on determining the transmission patterns of the disease in this endemic region.

The ability of naive participants to report symptoms of post-traumatic stress disorder.

OBJECTIVE: Research suggests that naive participants can simulate PTSD (post-traumatic stress disorder) using a symptom checklist. Is successful faking of DSM-IV criteria B-D on PTSD checklists due to prior knowledge of PTSD, the leading nature of symptom checklists, or a combination? DESIGN: Between-groups design. METHOD: Naïve participants self-generated PTSD symptoms from a vignette. They were then randomly assigned to groups given a standard symptom checklist or a checklist containing bogus items not normally associated with PTSD. RESULTS: Less than 1% self-generated symptoms that met DSM-IV criteria B-D for PTSD. It was found that 94% of participants satisfied these criteria using the standard checklist and 90% on the modified checklist. Participants incorrectly identified 38% of bogus symptoms as symptoms of PTSD. CONCLUSIONS: Despite poor prior knowledge of PTSD, 94% of participants fulfilled diagnostic criteria using a standard checklist. This is probably due to symptom 'guessing'.

Input space versus feature space in kernel-based methods.

This paper collects some ideas targeted at advancing our understanding of the feature spaces associated with support vector (SV) kernel functions. We first discuss the geometry of feature space. In particular, we review what is known about the shape of the image of input space under the feature space map, and how this influences the capacity of SV methods. Following this, we describe how the metric governing the intrinsic geometry of the mapped surface can be computed in terms of the kernel, using the example of the class of inhomogeneous polynomial kernels, which are often used in SV pattern recognition. We then discuss the connection between feature space and input space by dealing with the question of how one can, given some vector in feature space, find a preimage (exact or approximate) in input space. We describe algorithms to tackle this issue, and show their utility in two applications of kernel methods. First, we use it to reduce the computational complexity of SV decision functions; second, we combine it with the Kernel PCA algorithm, thereby constructing a nonlinear statistical denoising technique which is shown to perform well on real-world data.

Echinococcus granulosus infections of dogs in the Durazno region of Uruguay.

The prevalence and distribution of Echinococcus granulosus in domestic dogs was examined in three dog populations in the Durazno region of Uruguay. The prevalence was 19.7 per cent in 704 dogs successfully purged with arecoline hydrobromide. Higher prevalences were detected in dogs from the rural area (30.0 per cent) and the village of La Paloma (25.9 per cent) than in the town of Sarandi del Yi (7.9 per cent). The frequency distribution of E granulosus was overdispersed (k, the negative binomial parameter = 0.08), with only a few animals harbouring heavy infections. The results of a questionnaire showed that the prevalence was greatest in male dogs, in dogs that were not kennelled, in dogs that had access to fields and in dogs that were not dosed with praziquantel. Dogs that were given raw sheep offal by their owners were no more likely to be parasitised than other dogs; this may reflect the inaccuracy of the owners' replies, or that the dogs were being infected outside their home.

LeRec: a NN/HMM hybrid for on-line handwriting recognition.

We introduce a new approach for on-line recognition of handwritten words written in unconstrained mixed style. The preprocessor performs a word-level normalization by fitting a model of the word structure using the EM algorithm. Words are then coded into low resolution "annotated images" where each pixel contains information about trajectory direction and curvature. The recognizer is a convolution network that can be spatially replicated. From the network output, a hidden Markov model produces word scores. The entire system is globally trained to minimize word-level errors.

[First diagnosis of celiac disease in a 67-year old female patient]. / Erstdiagnose einer einheimischen Sprue bei einer 67-jährigen Patientin.

HISTORY AND CLINICAL FINDINGS: A 67 year old female patient presented herself to our emergency room with paraesthesia in both hands, chronic diarrhea and continuous weight loss. From the past medical history, only an autoimmune hypothyroidism was known. On initial, examination leading features were carpopedal spasms and a pulse deficit. Her general condition, especially the nutritional status was low. INVESTIGATIONS: Serum levels of potassium (2.2 mmol/l) and calcium (1.45 mmol/l) were low, as well as the levels of total protein (5.1 g/dl) and albumin (2.94 g/dl). Clotting time was prolonged (Quick 51%). The ECG showed a ventricular bigeminus and a prolonged QT-period (120% rel). Endoscopy and biopsy showed a total villous atrophy suggesting celiac disease as probable cause. This was emphasized by the high antibody levels against gliadin (1:80) and endomyosin (1:40). Furthermore, the Human Leukocyte Antigen molecules HLA-B8 and HLA-DR3 showed increased expression. TREATMENT AND COURSE: After normalizing the electrolyte imbalance intravenously the neurological symptoms disappeared as well as the arrhythmia. The QT-period went back to normal. Under initial drip feeding and a strict gluten-free diet the general condition improved quickly and the diarrhea stopped. A follow-up investigation 3 months later showed the woman in a good condition having gained 10 kg weight and an improvement in histological findings, so that diagnosis of celiac disease could be proved. CONCLUSIONS: The possibility of ventricular arrhythmia and a prolonged QT-period in the ECG should be taken into account for patients diagnosed with celiac disease, especially in case of electrolyte imbalance. In these cases addition to a strict gluten free diet a rapid correction of the electrolyte imbalance is necessary because of the risk of sudden cardiac death. Furthermore associated disorders like autoimmune diseases expressing the same HLA-antigens (HLA-B8 and HLA-DR3) must be considered. Combined incidence of celiac disease and autoimmune hypothyroidism is well documented. For patients with celiac disease we therefore recommend a routine testing of thyroid hormone levels.