Nicotine reduces antisaccade errors in task impaired schizophrenic subjects

Nicotine and/or smoking have been shown to reduce various cognitive deficits associated with schizophrenia. Here, we examine the effects of nicotine gum on repeated performance on a simple eye movement task. Eight schizophrenic subjects and eight controls participated in three days of testing on saccade (S) and antisaccade (AS) tasks. On each testing day, subjects participated in four testing sessions and received both of two nicotine gum treatments (4 and 6 mg) and both of two control conditions (placebo gum and no gum), each followed by a recovery period. Overall, schizophrenics showed significant impairments on the AS task. However, upon individual examination only four schizophrenics showed significant differences in AS errors or reaction times (RTs) when compared to controls. The other four schizophrenic subjects showed control level performance. All schizophrenic subjects showed normal and better than control level performance on the simple S task. Furthermore, no effects of nicotine were seen on the simple S task. There were significant treatment effects on the AS task. Nicotine treatment significantly decreased errors in the task impaired schizophrenic group and this effect was most pronounced at the 6 mg level. No nicotine effects were demonstrated for non-impaired schizophrenic subjects or controls. This study demonstrates a benefit of short exposure to nicotine in cognitively impaired schizophrenic subjects. These results support previous findings of cognitive benefits of nicotine in schizophrenics.     

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.     

A comparison of the discriminative stimulus effects of delta(9)-tetrahydrocannabinol and O-1812, a potent and metabolically stable anandamide analog, in rats

Efforts to determine whether Delta(9)-tetrahydrocannabinol (Delta(9)-THC) and anandamide elicit similar discriminative stimulus effects have yielded conflicting results. The difficulty in establishing a discriminative cue to anandamide may be due to its metabolic instability. Rats were trained to discriminate either Delta(9)-THC or O-1812, a metabolically stable anandamide analog, from vehicle to avoid this issue. O-1812 and Delta(9)-THC substituted for each other; however, both drugs were more potent in the O-1812-trained rats. Further, O-1812 only substituted for Delta(9)-THC at response rate decreasing doses. The CB(1) antagonist, SR141716A, blocked the discriminative stimulus effects of both drugs but augmented their rate effects. O-1839, a VR(1) agonist, failed to substitute for either cannabinoid. These results suggest that the discriminative stimulus effects of Delta(9)-THC and O-1812 are similar, but subtle differences also exist.     

Distal spinal muscular atrophy of upper limb (Hirayama disease) associated with high serum lead levels

Hirayama disease causes unilateral or asymmetrical bilateral distal weakness and atrophy of upper limbs. We report a 6 1/2-year-old female with Hirayama disease and associated high serum lead levels. This report highlights the occurrence of this condition in younger children and the need to further study the role of lead in its pathophysiology.     

The influence of prematurity and long chain polyunsaturate supplementation in 4-week adjusted age baboon neonate brain and related tissues

Clinical studies show that docosahexaenoic acid (DHA) and arachidonic acid (ARA) supplemented formula improve visual function in preterm infants, however improved fatty acid status is known only for plasma and red blood cells (RBC) since target organs cannot be sampled from humans. Baboons were randomized to one of four groups: Term breast-fed (B); Term formula-fed (T-); Preterm formula-fed (P-); and Preterm DHA/ARA-supplemented formula-fed (P+). The P+ contained 0.61 +/- 0.03% DHA and 1.21 +/- 0.09% ARA, and breast milk had 0.68 +/- 0.22% and 0.62 +/- 0.12% as DHA and ARA, respectively. The B and P+ groups had significantly higher DHA concentration in all tissues than T- and P-. The P- group showed dramatically lower DHA content of 35%, 27%, 66%, and 75% in the brain, retina, liver, and plasma, respectively, compared with B. Supplementation prevented declines in DHA levels in the retina, and liver, and attenuated the decline in brain, plasma and RBC of preterm animals. In contrast, ARA was not significantly lower compared with B in any group in any tissue but was significantly elevated in liver and brain. RBC and plasma DHA were correlated with DHA in tissues; RBC/plasma ARA were uncorrelated with tissue ARA. We conclude that 1) DHA drops precipitously in term and preterm primates consuming formula without long chain polyunsaturates, while 22:5n-6 concentration rises; 2) tissue ARA levels are insensitive to dietary LCP supplementation or prematurity, 3) plasma and RBC levels of ARA are uncorrelated with total ARA levels; 4) DHA levels are correlated with group effects and are uncorrelated within groups.     

Antibody response to pneumococcal capsular polysaccharides in children with acute otitis media

BACKGROUND: To describe the antibody response to pneumococcal capsular polysaccharides in children <2 years of age with pneumococcal acute otitis media (AOM) caused by serotypes 6A, 6B, 11A, 14, 19F or 23F. These serotypes were commonly found in both nasopharyngeal carriage and AOM in children of the study population in Finland. METHODS: Serum antibody concentrations to pneumococcal capsular polysaccharides of types 6B, 11A, 14, 19F and 23F were measured by enzyme immunoassay in acute and convalescent sera from children with AOM. RESULTS: Responses (at least 2-fold increase of antibody concentration) were relatively infrequent and varied with both the age of the child and the serotype of the Streptococcus pneumoniae isolated from the middle ear fluid. Children older than 12 months were more likely to have antibody responses than were younger children. Responses were seen only infrequently to types 6A, 6B or 19F (1 of 14, 1 of 9 and 2 of 25, respectively), more often to types 11A and 14 (2 of 8 and 3 of 8) and relatively frequently to type 23F (8 of 18). However, the convalescent antibody concentrations to type 23F were low and usually declined after the infection, whereas responders to 14 AOM had antibodies that persisted at a high concentration through the follow-up. CONCLUSIONS: The results emphasize the differences between Streptococcus pneumoniae serotypes in their immunogenicity and quantitative and qualitative differences of antibodies produced after infection.     

Selection of a thiazole urea-resistant variant of bovine viral diarrhoea virus that maps to the RNA-dependent RNA polymerase

By passing wild type bovine viral diarrhoea virus (BVDV) in increasing concentrations of DPC-A69280-29, a thiazole urea class compound that inhibits BVDV replication, we were able to select several variants of BVDV that exhibited decreased susceptibility to this compound. When the non-structural genes of these variants were sequenced and compared with wild type, only one change was common to all the variants that also exhibited resistance to DPC-A69280-29 (>10-fold increase in IC50). This change was a T-to-A transversion at position 11198 of the BVDV genome, which would cause a predicted substitution of isoleucine for phenylalanine at amino acid 78 of the RNA-dependent RNA polymerase (RdRp). This substitution would occur in a region of the BVDV RdRp which has been proposed to be important for the formation of the RdRp homodimer that is essential for the activity of the enzyme. However, since DPC-69280-29 inhibits BVDV replication by interfering with the initiation of viral RNA synthesis, we discuss the possibility that this region of the BVDV RdRp also may play a role in the initiation process. Furthermore, since this region is located fairly close to the template RNA, we also propose that the role it plays may involve either template selection, stabilization or processivity.     

Social representations of HIV/AIDS in Central and Eastern Europe

Although a relatively recent epidemic, HIV is now increasing in Eastern Europe faster than anywhere else in the world. In the study reported in this paper, we interviewed 511 business people and health professionals in five Central and Eastern European nations: Estonia, Georgia, Hungary, Poland and Russia, deriving our questions primarily from a Social Representations perspective. Respondents also freely completed their associations with the stimulus word 'AIDS'. Our findings indicate that, although there is considerable agreement about the threat posed by the epidemic, there are also notable cultural differences in attributions about the origin and spread of the virus and the nature of those groups at risk of infection. These findings are interpreted in the light of the historical legacies of the Communist era, as well as the real economic and social challenges faced by the population of this region.     

Mites in facilities for laboratory animals

OBJECTIVES: Two laboratory animal facilities were examined for storage and house-dust mites. METHODS: Samples of settled dust or material were investigated microscopically, and all of the found mites were identified. RESULTS: Every fourth sample contained mites. On the average, 86 mites were found in a gram of dust. Measurement with a two-way enzyme-linked immunosorbent assay revealed only one sample containing a minor amount of allergen from Dermatophagoides pteronyssinus. CONCLUSIONS: It seems that, in addition to house-dust mites, other mites may be important occupational contaminants in animal facilities.     

The contribution of lifestyle factors to socioeconomic differences in obesity in men and women--a population-based study in Sweden

BACKGROUND: The objective was to investigate whether and to what extent the association between socioeconomic status and obesity can be explained by lifestyle factors. METHODS: The relationship between socioeconomic status (SES) and obesity, and the role of lifestyle factors such as smoking, physical activity, heavy alcohol use, avoidance of dietary fat and propensity to eat fiber-rich food, was studied in a cross-sectional population-based study consisting of 6394 men and women aged 25-74 years in V?rmland County in Sweden. Educational level was used for measuring SES. The contribution of the measured lifestyle factors was assessed using logistic regression models. RESULTs: 12% of men and 14% of women were obese. Subjects with high education were leaner than subjects with low education, except among elderly women (65-74 years). Although many lifestyle factors were related to obesity and SES in this study, only a part (18-29%) of the association between educational level and obesity could be explained by the measured lifestyle factors. Physical inactivity and heavy alcohol use were the main factors contributing to this association, whereas smoking and the measured dietary attitudes towards fat and fiber had little additional effect. CONCLUSIONS: The findings of this study are consistent with the view that socioeconomic differences in obesity and its consequences can only partly be reduced by changes in lifestyle. Longitudinal studies, a more detailed investigation of the role of dietary factors and more studies including elderly subjects are, however, recommended to further elucidate the association between SES and obesity.