Household survey of dengue infection in central Brazil: spatial point pattern analysis and risk factors assessment

Urban dengue fever is now considered a major public health threat in most American countries. A household survey was conducted in the city of Goiania in central Brazil in 2001 to assess prevalence of dengue infection and individual and area-based risk factors. Spatial point pattern analysis was performed using the dual Kernel method. A total of 1,610 households were surveyed; 1,585 individuals more than five years old had blood and data collected. Sera were tested for IgM/IgG antibodies by an enzyme-linked immunoassay. Area-based indicators derived from census data were linked to geocoded residential address. The seroprevalence of dengue was 29.5% and the estimate prevalence surface reached 50% in the outskirts areas. The risk of infection was significantly associated with older age (P < 0.01), low education (odds ratio [OR] = 3.45, 95% confidence interval [CI] = 1.82-6.55), and low income (OR = 1.32, 95% CI = 1.02-1.71) in multivariate analysis. This study highlighted the heterogeneity of dengue transmission within the city and can assist in spatial targeting control interventions.     

Primula obconica– is contact allergy on the decline?

Primula obconica, a member of the Primulaceae family, was introduced to Britain from China in 1880. P. obconica cultivars, which are reputed to contain less primin, have been developed over the past number of years in an attempt to reduce the incidence of allergic contact dermatitis. Primin (2-methoxy-6-pentyl-1,4-benzoquinone) is the main sensitizer, although other allergens have been postulated. We believe the incidence of primula allergic contact dermatitis has fallen since the introduction of primin-free P. obconica into the European market and thus the aims of this study were twofold. First, to determine whether the incidence of primula allergic contact dermatitis was truly on the decline and, second, to confirm the presence of primin-free P. obconica in the UK. We surveyed the incidence of primula allergic contact dermatitis in the UK and compared the incidence in the period between 1995 and 2000 with a subsequent follow-up study looking at the incidence for 2002. The results showed a significant fall in primin-positive patch tests from 1995 to 2000. The follow-up results for 2002 showed a further reduction in the number of primin-positive patch tests. The yearly incidence of contact allergy to primin has fallen from 0.785% in 1995/1996 to 0.429% in 2002. This downward trend was statistically significant (P = 0.001). A telephone survey of UK seed suppliers and selected plant retailers was also undertaken to clarify what types of P. obconica were available for sale and to assess suppliers' and retailers' knowledge of the primin-free varieties. This survey showed that 50% of suppliers were selling primin-free varieties but that the majority of surveyed retailers were not currently selling any variety of P. obconica. Our study suggests that although the yearly incidence of contact allergy to primin has fallen significantly over the past 8 years, it is still an important allergen, and thus its inclusion in the standard series remains justified for the foreseeable future.     

Point-of-care ecarin clotting time versus activated clotting time in correlation with bivalirudin concentration

INTRODUCTION: A thrombin inhibitor management (TIM) point-of-care test based upon the ecarin clotting time (ECT) has been developed. The ECT has been suggested to more accurately reflect the anti-coagulant effect of direct thrombin inhibitors compared with the activated clotting time (ACT). We sought to examine the correlation of the TIM-ECT test with bivalirudin concentration in patients undergoing percutaneous coronary intervention (PCI), and to compare the performance of this test with the current standard (i.e., ACT). MATERIALS AND METHODS: In a multicenter study, blood samples were obtained at six pre-defined time-points in 170 consecutive patients undergoing PCI using bivalirudin. For each sample, the TIM-ECT (citrated and non-citrated), ACT, and bivalirudin concentration was determined. RESULTS: Considering samples from all time-points (n=784), the correlations of TIM-ECT citrated, TIM-ECT non-citrated, and ACT with bivalirudin concentration were 0.96, 0.93, and 0.90, respectively. For samples collected at therapeutic levels of bivalirudin (n=353), the correlations of TIM-ECT citrated, TIM-ECT non-citrated, and ACT with bivalirudin concentration were lower, and showed a greater disparity between methods, with correlation coefficients of 0.75, 0.59, and 0.37, respectively. Prediction models based on the measured bivalirudin concentration were developed for TIM-ECT and ACT, and the coefficients of determination (r(2)) of actual versus predicted TIM-ECT and ACT were 0.91 and 0.81, respectively. CONCLUSIONS: In this PCI population, the TIM-ECT point-of-care test and ACT demonstrated a strong correlation with bivalirudin concentration. The TIM-ECT test had a higher correlation with bivalirudin concentration at therapeutic levels of the drug, and for individual samples appears to more consistently reflect the bivalirudin concentration compared with the ACT.     

Protein synthesis, PKA, and MAP kinase are differentially involved in short- and long-term memory in rats

We studied the involvement of hippocampal protein synthesis-, PKA-, and MAP kinase-dependent processes in short- (STM) and long-term memory (LTM) for inhibitory avoidance task. Fifteen minutes before or immediately after training rats received intrahippocampal infusions of vehicle, the protein synthesis inhibitor anisomycin, the PKA inhibitor Rp-cAMPs or the MAPKK inhibitor PD098059. The results show that STM recruits PKA and MAPK, whereas, LTM depends on PKA activity and protein synthesis during the early post-training period.     

Progressive multifocal leukoencephalopathy successfully treated with highly active antiretroviral therapy and cidofovir in an adolescent infected with perinatal human immunodeficiency virus (HIV)

Progressive multifocal leukoencephalopathy is an infectious demyelinating brain disease caused by the JC virus that is associated with significant morbidity and mortality in the immunocompromised host. We report a case of progressive multifocal leukoencephalopathy successfully treated with highly active antiretroviral therapy and cidofovir in an adolescent patient perinatally infected with human immunodeficiency virus (HIV).     

Diffusion-weighted imaging and proton magnetic resonance spectroscopy in perinatal hypoxic-ischemic encephalopathy: association with neuromotor outcome at 18 months of age

We evaluated early diffusion-weighted imaging findings, the quantitative apparent diffusion coefficient, and magnetic resonance spectroscopy (the presence of lactate and ratios of N-acetylaspartate to total creatine and choline to total creatine) in the prediction of the 18-month neuromotor outcome of term newborns with hypoxic-ischemic encephalopathy. Conventional T1- and T2-weighted and diffusion-weighted imaging was performed in 20 asphyxiated term newborns, with additional basal ganglia magnetic resonance spectroscopy in 15 newborns between 2 and 18 days of life (mean 7.3 days). Neuromotor outcome was dichotomized into normal and abnormal for statistical analysis. Statistically significant differences in the ratios of N-acetylaspartate to total creatine, but not apparent diffusion coefficient values and ratios of choline to total creatine, were found between infants with a normal and an abnormal outcome (Mann-Whitney U-test, P = .010). There was a significant association between the presence of a lactate peak and an abnormal outcome (chi-square test, P = .017). The presence of a lactate peak for predicting an abnormal outcome had a sensitivity of 100% and a specificity of 80%, and the odds ratio was 37.4. Ischemic lesions were more conspicuous and/or extensive on diffusion-weighted imaging in all except one neonate. The presence of normal findings on both diffusion-weighted imaging and conventional magnetic resonance imaging is predictive of a normal neuromotor outcome, whereas lactate and a reduced ratio of N-acetylaspartate to total creatine in the basal ganglia, but not an apparent diffusion coefficient, are associated with an abnormal outcome at 18 months of age.     

Activation in the anterior left auditory cortex associated with phonological analysis of speech input: localization of the phonological mismatch negativity response with MEG

The spatio-temporal dynamics of cortical activation underlying auditory word recognition, particularly its phonological stage, was studied with whole-head magnetoencephalography (MEG). Subjects performed a visuo-auditory priming task known to evoke the phonological mismatch negativity (PMN) response that is elicited by violations of phonological expectancies. Words and non-words were presented in separate conditions. In each of the 318 trials, the subjects first saw a word/non-word (e.g., 'cat') that was soon followed by a prime letter (e.g., 'h'). Their task was to replace mentally the sound of the first letter of the word/non-word with the prime letter, thus resulting in a new word/non-word (e.g., 'hat'). Finally, an auditory word/non-word either matching or mismatching with the anticipated item was presented. In most subjects, a PMNm followed by a later, N400m-like negativity was obtained in the left hemisphere to the mismatching auditory stimuli. A similar response pattern was obtained in the right hemisphere only in a few subjects. Source localization of the N1m, an index of acoustic analysis, and the PMNm and N400m-like responses was performed using L1 minimum-norm estimation. In the left hemisphere, the PMNm source for the words was significantly more anterior than the source of the N400m-like response; for the non-words, the PMNm source was significantly more anterior than the sources of the N1m and the N400m-like response. These results suggest that the left-hemisphere neuronal networks involved in sub-lexical phonological analysis are at least partly different from those responsible for the earlier (acoustic) and later (whole item) processing of speech input.     

Electrophysiological correlates of object categorization: back to basics

The time course of visual object categorization as a function of electrophysiological activity in the brain was investigated using a variant of the "oddball" design. Category level was manipulated by sequentially presenting subordinate, basic or superordinate target objects among a variety of non-target objects. It was found that superordinate categorizations were performed more quickly and differentiated from basic level categorizations in amplitude early in visual processing (320-420 ms). In contrast, subordinate categorizations took longer to perform and differentiated from basic level categorizations in amplitude and latency at later stages (450-550 ms). Notably, these effects were observed using the same objects categorized at different levels suggesting that visually categorizing objects at varying levels of abstraction engaged specific cognitive processes. These results are consistent with research on rapid visual categorization that challenges the generality of basic category level superiority effects.