Telling good from bad news: ADHD differentially affects processing of positive and negative feedback during guessing

Neuroimaging studies on ADHD suggest abnormalities in brain regions associated with decision-making and reward processing such as the anterior cingulate cortex (ACC) and orbitofrontal cortex. Recently, event-related potential (ERP) studies demonstrated that the ACC is involved in processing feedback signals during guessing and gambling. The resulting negative deflection, the 'feedback-related negativity' (FRN) has been interpreted as reflecting an error in reward prediction. In the present study, ERPs elicited by positive and negative feedback were recorded in children with ADHD and normal controls during guessing. 'Correct' and 'incorrect' guesses resulted in respectively monetary gains and losses. The FRN amplitude to losses was more pronounced in the ADHD group than in normal controls. Positive and negative feedback differentially affected long latency components in the ERP waveforms of normal controls, but not ADHD children. These later deflections might be related to further emotional or strategic processing. The present findings suggest an enhanced sensitivity to unfavourable outcomes in children with ADHD, probably due to abnormalities in mesolimbic reward circuits. In addition, further processing, such as affective evaluation and the assessment of future consequences of the feedback signal seems to be altered in ADHD. These results may further help understanding the neural basis of decision-making deficits in ADHD.     

Wear of aluminum oxide antagonists by commercially available composites and compomers

PURPOSE: To investigate the wear of aluminum oxide antagonists by 19 light curing, commercially available composites and compomers. The influence of the filler particle size of the composites, the filler particle material and the filler particle morphology was determined. METHODS: Occlusal contact wear of the antagonists was simulated in a sliding wear test. Eight antagonists and specimens of each material were tested in a pin-on-block design with oscillating sliding of an aluminum oxide antagonist (Degussit antagonist, 5 mm diameter). After 50,000 cycles the contact area was evaluated using a dedicated software (UTHSCA image tool for windows V 2.0) under a light microscope. The size of the contact area was measured. RESULTS: Three types of boundaries of the contact area could be observed: (1) Sharp boundary, (2) No sharp boundary but easy to identify, and (3) No sharp boundary and difficult to identify. The method of Pearson was used to calculate the correlation coefficients. The coefficient of determination between the ranking of the measured contact area and the ranking of the maximum particle size was r2= 0.46 (P> 0.05). Composite materials with the same particle size were ranked by their filler content (wt. %).     

Durability of extensive Class II open-sandwich restorations with a resin-modified glass ionomer cement after 6 years

PURPOSE: To evaluate the durability of a modified open-sandwich restoration utilizing a resin-modified glass ionomer cement (RMGIC) in large cavities. METHODS: 268, mostly extensive, Class II Vitremer/Z100 restorations were placed in 151 patients. 47% of the restorations were placed in patients considered as caries-risk patients. Six experimental groups, differing from each other in thickness of RMGIC layer and preconditioning, were evaluated at baseline and annually during 6-7 years according to modified USPHS criteria. RESULTS: After 6 years, 220 restorations were evaluated. 42 failures (19%) were observed. The most frequent reasons for failure were material fracture (n = 11), tooth fractures (n = 9) and secondary caries (n = 10). Non-acceptable proximal dissolution of the RMGIC was seen in six restorations. Significantly more failures, but similar dissolution of the RMGIC, were recorded in high caries risk patients. No differences were seen between the experimental groups or between restorations with thick or thin RMGIC layer. 160 restorations were also evaluated at 7 years. Another 13 failures were observed, eight with non-acceptable dissolution, three secondary caries and two fractures. It can be concluded that the modified open sandwich restoration showed an acceptable durability for the extensive restorations evaluated. An accelerating dissolution of the RMGIC was observed at the end of the study.     

Neuronal expression of caspase-1 immunoreactivity in the rat central nervous system

Caspase-1/interleukin-1beta (IL-1beta)-converting enzyme (ICE) cleaves IL-1beta and IL-18 precursor proteins to the active forms of these proinflammatory cytokines. Since both cytokines are constitutively expressed in the brain, we investigated whether this is also the case for caspase-1. Using an antibody raised against the p10-subunit of the active enzyme, constitutive expression of caspase-1 immunoreactivity was found in nerve cells in the arcuate nucleus and in nerve fibres throughout the brain. Co-localisation with alpha-melanocyte stimulating hormone was demonstrated. The distribution pattern of caspase-1 immunoreactive structures is consistent with a role to produce mature IL-1beta in regions where IL-1beta mediates fever and sleep.     

Central nervous system effects of acute organophosphate poisoning in a two-year follow-up

OBJECTIVES: Patients hospitalized for acute organophosphate poisoning in León, Nicaragua, were followed for effects on the central nervous system (CNS) over a 2-year period. METHODS: Immediate verbal memory (Rey verbal learning), visuomotor performance (digit symbol), and neuropsychiatric symptoms (Q-16) were assessed for 53 poisoned persons at the time of hospital discharge, 7 weeks postpoisoning, and 2 years postpoisoning, and, at the same time intervals, for 28 persons who had never been poisoned. The poisonings were classified as moderate occupational (31), severe occupational (15), and severe through the oral route (7), representing low, medium, and high exposure, respectively. Longitudinal confounder-adjusted between-category comparisons and longitudinal analyses of variance and covariance were used to assess the effects of the exposure. RESULTS :Immediate verbal learning showed deficits in the high-exposure group, in particular at the time of discharge, but the estimate of the difference when compared with the values of the unexposed was imprecise. Visuomotor performance showed a deficit at 7 weeks in the medium-exposure group, but it had improved after 2 years relative to that of the unexposed, for whom improvement had occurred at 7 weeks and persisted during the 2 years of follow-up, possibly a test-retest effect. Neuropsychiatric symptoms were in excess 2 years after the hospital discharge in the low- and medium-exposure groups and all the groups combined. All the results were imprecise for the small high-exposure group. CONCLUSIONS: Visuomotor performance and possibly short-term verbal memory seem to be affected early after severe acute organophosphate poisoning and recover, either truly or by some compensatory mechanism. Neuropsychiatric symptoms seem to increase after a longer latency period.     

Loss of 14q31-q32.2 in renal cell carcinoma is associated with high malignancy grade and poor survival

The present study was undertaken to further approach the importance of 14q deletions in renal cell carcinoma (RCC) development. The initial screening using 2 RFLP markers from distal 14q identified loss of heterozygosity (LOH) in 17 of 45 informative cases (38%). In addition, in 37 patients with primary RCCs, it was shown that cases with LOH at D14S1 had significantly shorter survival as compared to cases with-out LOH (p<0.005). Subsequently, 19 primary tumors and 6 metastases were genotyped for 20 polymorphic markers and the findings were evaluated in relation to the clinical characteristics of the primary tumor and the survival during follow-up. Overall LOH was identified in 11 of the primary tumors (58%) and 4 of the metastases (66%). In metastases as well as in primary tumors the highest frequency of LOH was detected with markers from the distal part of the chromosome i.e., 14q32. Five minimal regions of overlapping deletions were identified, three of which (II, IV and V) were defined from the primary RCCs. From centromere to telomere these include region I proximal of D14S259, region II between D14S255 and D14S588, region III in the D14S61-D14S617 interval, region IV between D14S617 and D14S260, and region V telomeric of D14S1007. For the primary tumors, losses in regions IV and V were each significantly associated with high tumor grade (i.e., grade 3; p<0.05). Furthermore, LOH within region IV was also associated with a significantly shorter survival (p=0.02). In conclusion, the high frequency of distal 14q LOH supports the relevance of this alteration for the development of RCC.     

The combined analysis of P-glycoprotein expression and activity predicts outcome in childhood acute lymphoblastic leukemia

The link between drug resistance and relapse was often suggested, but rarely demonstrated in long-range clinical studies. Since it is nowadays recommended to validate immunocytochemical results, the authors studied prospectively 52 acute lymphoblastic leukemia (ALL) patients with an immunocytochemical test and a functional flow cytometric test. The 4-year EFS and OS were 79.3% and 85.2%, respectively. Patients scoring positive in both tests had a significantly higher relapse rate and worse survival (log rank p = .007 and .047 for event-free survival and overall survival, respectively). Among the different prognostic variables evaluated, only the combination of P-gp expression and activity was a statistically significant parameter predicting relapse in childhood ALL.     

Large-scale genotyping of single nucleotide polymorphisms by Pyrosequencingtrade mark and validation against the 5'nuclease (Taqman((R))) assay

Here we present the first large-scale effort at genotyping using a novel sequencing method, Pyrosequencingtrade mark, as a method for genotyping of single nucleotide polymorphisms (SNPs). Pyrosequencingtrade mark genotypes were validated through duplicate analysis of 1,022 genotypes using the PSQ96trade mark instrument for pyrosequencing and TaqMan((R)) for 5'nuclease assays. Identical results were obtained using both methods. In a small pilot study, a pooling strategy using Pyrosequencingtrade mark was successfully tested. We conclude that Pyrosequencingtrade mark is highly efficient and accurate in the analysis of SNPs and represents a promising solution to high-throughput genotyping of large sample populations.     

Capecitabine monotherapy and in combination with immunotherapy in the treatment of metastatic renal cell carcinoma

This prospective trial aimed to evaluate the therapeutic effects and systemic toxicities of capecitabine monotherapy and capecitabine treatment combined with biological response modifiers in patients with metastatic renal cell carcinoma. Fifty-four patients suffering from metastatic renal cell carcinoma progressing under first-, second- or third-line treatment entered the trial. Capecitabine was given orally at a dose of 2500 mg/m2 daily divided into two doses for 14 days, followed by a 7-day rest in the monotherapy as well as in the combination treatment. This schedule was repeated in 3-week cycles. The combination therapy consisted of capecitabine and an immunotherapy treatment, which consisted either of interferon (IFN)-gamma1b (100 mg/day) administered consecutively 5 times weekly during weeks 1 and 2, and recombinant interleukin (IL)-2 (4.5 MU/day) administered on 4 consecutive days during weeks 3 and 4, every 6 weeks, or IFN-alpha (6 MioIE/day) administered 3 times a week. Fifty-two patients are now evaluable for response and 54 patients for toxicity. We observed a partial response to treatment in five patients (9.6%), minor response in five patients (9.6%), stable disease in 32 patients (61.6%) and only 10 patients (19.2%) showed continued disease progression despite treatment. Outpatient capecitabine was well tolerated. We did not observe any WHO grade IV toxicities. We conclude that capecitabine monotherapy and capecitabine treatment in combination with biological response modifiers appear to be effective regimens with favorable toxicity profiles in patients with advanced renal cell carcinoma. Capecitabine monotherapy seems to be superior than the combination treatment because of its easier application form.