Subjective visual awareness emerges prior to P3

Studies on the neural basis of visual awareness, the subjective experience of seeing, have found several potential neural correlates of visual awareness. Some of them may not directly correlate with awareness but with post‐perceptual processes, such as reporting one's awareness of the stimulus. We dissociated potential electrophysiological correlates of visual awareness from those occurring during response selection and thus co‐occurring with post‐perceptual processing. The participants performed two GO‐NOGO conditions. In the aware‐GO condition they responded with a key press when they were aware of the stimulus and withheld responding when they were unaware of it. In the unaware‐GO condition they withheld responding when they were aware and responded when they were not aware of the stimulus. Thus, event‐related potentials could be measured to aware and unaware trials when responding was required and when not required. The results revealed that the N200 amplitude (180–280 ms) over the occipital and posterior temporal cortex was enhanced in aware trials as compared with trials without awareness. This effect (visual awareness negativity, VAN) did not depend on responding. The amplitude of P3 (350–450 ms) also was enhanced in aware trials as compared with unaware trials. In addition, the amplitudes in the P3 time window depended on responding: they were greater when awareness was mapped to GO‐response than when not, suggesting that P3 reflects post‐perceptual processing, that is, it occurs after awareness has emerged. These findings support theories of visual awareness that assume a relatively early onset of visual awareness before P3.     

Size at birth, weight gain over the life course, and low-grade inflammation in young adulthood: northern Finland 1966 Birth Cohort study.

AIMS: Low-grade inflammation might mediate associations between size at birth, early life growth, excessive weight gain, and subsequent risk of cardiovascular disease in adult life. Our aim was to investigate relationships between fetal growth, weight over the life course, and low-grade inflammation measured by serum high sensitivity C-reactive protein (CRP) levels at 31 years. METHODS AND RESULTS: General population-based northern Finland 1966 Birth Cohort study of 5840 participants attending a clinical examination at 31 years, including measurement of CRP. Weight and height were assessed at birth, 12 months, and 14 and 31 years of age. CRP levels at 31 years were 16% [95% confidence interval (CI) 8, 23] higher per 1 kg lower birth weight, 21% (95% CI 2, 37) higher per 10 cm lower birth length, and 24% (95% CI 10, 36) higher per 1 kg/m3 lower ponderal index, after adjustment for potential confounders. Participants with highest tertile body mass index (BMI) at 31 years and lowest tertile birth weight had the highest average CRP levels. Per unit increase in BMI from 14 to 31 years was associated with 16% (95% CI 14, 17) higher CRP levels; the association was larger for those in the top BMI tertile at age 14 years. CONCLUSION: Systemic low-grade inflammation may lie on the causal pathway that relates impaired fetal growth and weight gain from childhood to adulthood to adverse adult cardiovascular health. Lifestyle changes from early life might be an important step in reducing cardiovascular risk in adults.     

Plasma orexin-A levels and body composition in COPD

STUDY OBJECTIVE: To study the role of orexins in regulating body composition in patients with COPD. DESIGN: Prospective study. Patients and measurements: We measured the plasma concentration of orexin-A in 20 patients with COPD and compared the results to those obtained from 10 age-matched control subjects. Patients with COPD were classified into two groups based on their body mass index (BMI): a normal weight (NW) group (BMI > 20) and an underweight (UW) group (BMI < 20). RESULTS: The plasma orexin-A level was significantly lower in patients with COPD than in control subjects. In patients with COPD, the level was significantly lower in the UW group than in the NW group. Plasma orexin-A levels significantly correlated with BMI and fat mass values, but there was no significant relationship between plasma orexin-A levels and the fat-free mass of patients with COPD. CONCLUSION: These results suggest that orexin-A levels are altered with weight loss and changes in body composition in patients with COPD.     

Coronary heart disease: from a disease of middle-aged men in the late 1970s to a disease of elderly women in the 2000s.

AIMS: To analyse secular changes in the prevalence of coronary heart disease (CHD) and to assess changes in the burden of CHD at population level. METHODS AND RESULTS: Data were used from two large cross-sectional health examination surveys representing the entire Finnish adult population in 1980 and 2000. In the 1978-80 survey, the sample covered 5101 individuals aged > or =45, of whom 88% participated. The 2000-2001 survey comprised 5310 individuals in the same age range. Participation rate in the health examination was 87%. Prevalence of CHD decreased in men and women under the age of 65 and increased among those aged > or =75. Prevalence of large Q-waves indicating previous myocardial infarction decreased in all male age groups and in women aged 65-74. The total estimated number of persons with CHD increased by 18% (95% CI=6-30) during the past 20 years in Finland. In 1980, the most dominant CHD group was men aged 45-64, whereas in 2000, women aged > or =75 comprised the largest CHD group. CONCLUSION: Although the prevalence of CHD has decreased among middle-aged persons, the number of CHD cases has increased during the past 20 years in Finland.     

Comparative evaluation of urine-based and other minimally invasive methods for the diagnosis of Helicobacter pylori infection

Background: Diagnostic methods have recently been developed for detecting anti-Helicobacter pylori antibody in urine and H. pylori antigen in stool samples. Our aim was to evaluate the usefulness of noninvasive urine-based methods for the diagnosis of H. pylori infection. Methods: The study subjects were 100 asymptomatic Japanese volunteers. We investigated the diagnostic efficacy of various noninvasive diagnostic methods; five serological tests (Immunis anti-pylori, HM-CAP, EIAgen Helicobacter pylori IgG, Helico G, and GAP-IgG), one test for antigen in stool (HpSA enzyme immunoassay [EIA]), and two tests for antibody in urine (Urinelisa and Rapirun) by using the urea breath test (UBT) as the gold standard. Results: Fifty subjects were diagnosed as positive for H. pylori infection by the UBT. The serological tests showed good sensitivity, specificity, and accuracy. The diagnostic values of the feces-based test (HpSA EIA) were lower than that of the serological tests. The sensitivities of the two urine-based methods in frozen urine samples were markedly lower than those of the other tests. However, the use of unfrozen samples markedly improved the diagnostic accuracy of these urine-based tests, which was then superior to that of the feces-based method. Conclusions: This study clearly showed that urine-based tests were useful for the diagnosis of H. pylori infection. However, the use of frozen urine samples was not appropriate for the detection of anti-H. pylori antibody. Received: November 5, 2001 / Accepted: February 22, 2002 Acknowledgments. We wish to thank Ms. Rika Tohma, Ms. Shiho Yamamoto, Ms. Yukiko Inoue, Mr. Masahiro Ishibashi, and Mr. Nobuo Sasaki for their technical supports. This work was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan. Reprint requests to: K. Adachi