Seroprevalence of toxocariasis in children aged 1-9 years in western Islamic Republic of Iran, 2003

We determined the seroprevalence of Toxocara canis infection in 544 children under 10 years randomly selected from urban and rural areas of Hamadan, An enzyme-linked immunosorbent assay was used for detection of antibodies to T. canis excretion - secretion antigens. Using a questionnaire, epidemiological factors associated with infection were examined, including age, sex, residence. Antibodies to T. canis were detected in 29 children (5.3%) and 19 children (3.5%) were categorized as borderline positive; thus together this gave a prevalence of toxocariasis of 8.8%. No significant differences were found in terms of sex, age and residence

Level sets and Composition operators on the Dirichlet space

We consider composition operators in the Dirichlet space of the unit disc in the plane. Various criteria on boundedness, compactness and Hilbert-Schmidt class membership are established. Some of these criteria are shown to be optimal

Association between Endothelial Selectin (E-selectin) gene polymorphisms and E-selectin level with visceral leishmaniais, in an ARMS-PCR based study

Background: In the visceral leishmaniasis (VL), parasites reside in reticuluendothelial system, mainly in macrophages. Endothelial Selectin (E-selectin) might play an important role in leukocyte-endothelium interactions and inflammatory cell recruitment. The aim of this study was determining E-selectin level and its polymorphism in three groups, patients, seropositive and healthy individuals. Methods: Serum soluble E-selectin levels as well as 2 polymorphisms of E-selectin (Ser128Arg and Leu554Phe) were measured in a cohort of patients with documented VL (n=64), a healthy control group (n=74) and a seropositive for VL but without any symptoms (n=81). Circulation concentration of E-selectin levels was measured by ELIS. The amplification refractory mutation system (ARMS)-PCR procedure was used for detecting polymorphisms. Results: The mean of E-selectin levels significantly differed between three groups (P<0.026), and were increased in patients in comparison with other groups. Difference was more considerable between two groups of patients and healthy ones (patients 92.8 ng/ml; healthy individuals 71.9 ng/ml). Polymorphisms were associated with soluble E-selectin levels and altogether explained 14.4%, 7.2%, and 8.7% in patients, seropositive and seronegative healthy individuals, respectively. Distribution of polymorphisms of 128Ser/Arg and 554Leu/Phe among three groups was not different significantly; however, there was a considerable arrangement in distribution of Ser128Arg polymorphism and 128Arg allele in healthy group was more than two fold of patients (55% against 20%). Conclusion: The association between soluble E-selectin levels and visceral leishmaniasis suggests that this molecule might have significant role in the inflammatory process in VL. Moreover, frequency of 128Arg allele in healthy group was higher than patients

Contrast Dependence of Smooth Pursuit Eye Movements following a Saccade to Superimposed Targets

Dorsal stream areas provide motion information used by the oculomotor system to generate pursuit eye movements. Neurons in these areas saturate at low levels of luminance contrast. We therefore hypothesized that during the early phase of pursuit, eye velocity would exhibit an oculomotor gain function that saturates at low luminance contrast. To test this, we recorded eye movements in two macaques trained to saccade to an aperture in which a pattern of dots moved left or right. Shortly after the end of the saccade, the eyes followed the direction of motion with an oculomotor gain that increased with contrast before saturating. The addition of a second pattern of dots, moving in the opposite direction and superimposed on the first, resulted in a rightward shift of the contrast-dependent oculomotor gain function. The magnitude of this shift increased with the contrast of the second pattern of dots. Motion was nulled when the two patterns were equal in contrast. Next, we varied contrast over time. Contrast differences that disappeared before saccade onset biased post-saccadic eye movements at short latency. Changes in contrast occurring during or after saccade termination did not influence eye movements for approximately 150 ms. Earlier studies found that eye movements can be explained by a vector average computation when both targets are equal in contrast. We suggest that this averaging computation may reflect a special case of divisive normalization, yielding saturating contrast response functions that shift to the right with opposed motion, averaging motions when targets are equated in contrast

Oculomotor feature discrimination is cortically mediated

Eye movements are often directed toward stimuli with specific features. Decades of neurophysiological research has determined that this behavior is subserved by a feature-reweighting of the neural activation encoding potential eye movements. Despite the considerable body of research examining feature-based target selection, no comprehensive theoretical account of the feature-reweighting mechanism has yet been proposed. Given that such a theory is fundamental to our understanding of the nature of oculomotor processing, we propose an oculomotor feature-reweighting mechanism here. We first summarize the considerable anatomical and functional evidence suggesting that oculomotor substrates that encode potential eye movements rely on the visual cortices for feature information. Next, we highlight the results from our recent behavioral experiments demonstrating that feature information manifests in the oculomotor system in order of featural complexity, regardless of whether the feature information is task-relevant. Based on the available evidence, we propose an oculomotor feature-reweighting mechanism whereby (1) visual information is projected into the oculomotor system only after a visual representation manifests in the highest stage of the cortical visual processing hierarchy necessary to represent the relevant features and (2) these dynamically recruited cortical module(s) then perform feature discrimination via shifting neural feature representations, while also maintaining parity between the feature representations in cortical and oculomotor substrates by dynamically reweighting oculomotor vectors. Finally, we discuss how our behavioral experiments may extend to other areas in vision science and its possible clinical applications

Genomic study of the cereolysin A and B genes in Bacillus cereus isolated from raw and pasteurized milk

Bacillus cereus spores are expanded in the nature and they can be separated from different foods. Cytotoxin is one of the most important poisons which is produced by Bacillus cereus, and it is highly resistant to heat and leads to diarrhea, nausea and vomiting syndrome. Hence study about existence of Bacillus cereus in pasteurized milk is very important due to probability of causing illness by Cereolysin gene products. Therefore, Different milk samples were collected from raw milk to pasteurized milk after various stages of producing pasteurized milk. Cultivation of milk samples in Mannitol egg yolk polymyxin B (MYP) media was done and it was followed by a purification of the observed colonies andinvestigation of cereolysin A and B by polymerase chain reaction (PCR) amplification. Thus, the gene was amplified and aligned with the previous sequences that were registered in the gene bank database. As such, many new missense mutations were observed at the amplified gene sequences. However these missense mutations caused a change in the sequence of amino acid at the protein chain but the protein efficiency and structure was not changed due to the substitution of amino acids with the sameproperties.Key words: milk- cereolysin - Bacillus cereus- polymerase chain reaction- gene