Brain oscillatory responses to an auditory-verbal working memory task in mild cognitive impairment and Alzheimer's disease.

We report preliminary findings on EEG oscillatory correlates of working memory in mild cognitive impairment (MCI) and Alzheimer's disease (AD). Event-related desynchronization (ERD) and synchronization (ERS) of the 1-20 Hz EEG frequencies were studied using wavelet transforms in elderly controls, MCI patients and mild probable AD patients performing an auditory-verbal Sternberg memory task. Behaviourally, the AD patients made more errors than the controls and the MCI group. Statistically significant differences during the encoding of the memory set were found between the controls and the MCI group, such that the latter group showed ERD in the approximately 10-20 Hz frequencies. The findings may reflect different, compensatory encoding strategies in MCI. During retrieval, the most obvious differences were observed between the controls and the AD group: the ERD in the approximately 7-17 Hz frequencies was absent in the AD group particularly in anterior and left temporal electrode locations. This finding might indicate that AD is associated with deficient lexical-semantic processing during the retrieval phase in working memory tasks. Future studies with larger patient groups are needed to establish the diagnostic value of ERD/ERS patterns in MCI and AD.     

Evaluation of a new cellulose sponge-tipped swab for microbiological sampling: a laboratory and clinical investigation

A new type of swab (Cellswab; Cellomeda, Turku, Finland), utilizing a highly absorbent cellulose viscose sponge material, was compared to some traditional swabs. The survival of 14 aerobic and 10 anaerobic and microaerophilic bacterial species in the Cellswab, two commercial swab transport systems (Copan, Brescia, Italy, and Orion Diagnostica, Espoo, Finland), and one Dacron swab (Technical Service Consultants Ltd. [TSC], Heywood, United Kingdom) was evaluated. Bacteria were suspended in broth, into which the swabs were dipped. The Cellswab absorbed 1.3 times more fluid and released 3.5 times more fluid upon plating than the other swabs. Aerobic bacteria were stored in dry tubes, the others in transport medium, at 4 degrees C and room temperature (RT), for up to 14 days. Swab samples were transferred to plates at 0, 1, 2, 4, 7, and 14 days. For 10 strains the Cellswab yielded > or =10% of the original CFU for longer than all the other swabs. In the clinical study, the ability of the Cellswab to detect beta-hemolytic streptococci from throat samples (n = 995) was compared to that of the TSC Dacron swab. The swabs performed equally, both when their samples were transferred to plates immediately and after storage for 1 day at 4 degrees C or RT. The changes in normal microbiota after storage were also similar. The Cellswab was found to perform at least as well as ordinary swabs. It was better at storing fastidious strains, and at keeping bacteria viable for long storage times; it might well be a useful replacement or complement to ordinary swabs.     

Salience of Guilty Knowledge Test items affects accuracy in realistic mock crimes.

Guilty Knowledge Test measuring electrodermal reactions was carried out in order to investigate the quality of different questions and the validity of the test in a situation that resembled a true crime. Fifty participants were randomly assigned to commit one of two realistic mock crimes, and were later tested with GKTs concerning both the crime they had enacted and the one they had no knowledge of. Different scoring systems (SCRs and peak amplitudes as well as raw and standardised scores) were employed and compared when analyzing the results. Although there were some false positives, the test was able to differentiate between the groups of guilty and innocent participants. With the best scoring systems, the test was able to classify up to 84% of the innocent and up to 76% of the guilty correctly according to a logistic regression analysis. ROC areas reflecting these same results reached values above .80. Questions on matters that demanded the participants' attention and were easier to remember had better discriminative power. With nearly all scoring methods, there was a significant interaction between the salience of the relevant items and the guilt of the participants. Participants reacted more strongly to salient relevant items when they were guilty, while no different reactions were observed for the non-salient items between guilty and innocent participants. It is suggested that, although the Guilty Knowledge Test appears to be a valid measure of guilty knowledge even in crimes that are close to real crimes, the principles on which guilty knowledge test questions are constructed should be more clearly specified.     

Quantitative measurement of regional lung gas volume by synchrotron radiation computed tomography

The aim of this study was to assess the feasibility of a novel respiration-gated spiral synchrotron radiation computed tomography (SRCT) technique for direct quantification of absolute regional lung volumes, using stable xenon (Xe) gas as an inhaled indicator. Spiral SRCT with K-edge subtraction using two monochromatic x-ray beams was used to visualize and directly quantify inhaled Xe concentrations and airspace volumes in three-dimensional (3D) reconstructed lung images. Volume measurements were validated using a hollow Xe-filled phantom. Spiral images spanning 49 mm in lung height were acquired following 60 breaths of an 80% Xe-20% O2 gas mixture, in two anaesthetized and mechanically ventilated rabbits at baseline and after histamine aerosol inhalation. Volumetric images of 20 mm lung sections were obtained at functional residual capacity (FRC) and at end-inspiration. 3D images showed large patchy filling defects in peripheral airways and alveoli following histamine provocation. Local specific lung compliance was calculated based on FRC/end-inspiration images in normal lung. This study demonstrates spiral SRCT as a new technique for direct determination of regional lung volume, offering possibilities for non-invasive investigation of regional lung function and mechanics, with a uniquely high spatial resolution. An example of non-uniform volume distribution in rabbit lung following histamine inhalation is presented.     

Haplotypic association of DDAH1 with susceptibility to pre-eclampsia

Association between pre-eclampsia (PEE1) and the dimethylarginine dimethylaminohydrolase (DDAH) 1 and 2 genes, which play a role in the regulation of nitric oxide synthesis and release, was studied. In a case-control study design single nucleotide polymorphisms (SNPs) were determined at eight sites in the DDAH1 gene and at one site (Pro231Pro) in the DDAH2 gene from 132 women with pre-eclampsia and 112 healthy controls. Three SNPs in the DDAH1 gene were associated with pre-eclampsia, showing complete linkage disequilibrium with each other, but none of the associations in the allele or genotype data reached statistical significance in either of the genes after the correction for multiple testing. Haplotype frequencies were estimated using a population based on a maximum likelihood method (EM algorithm). Four common DDAH1 haplotypes were present and a significant association of haplotypes H2 and H3 with pre-eclampsia (P=0.03) was found. The risk of pre-eclampsia was greatest in individuals (odds ratio: 3.93; 95% confidence interval: 1.54-9.99) who had two copies of the high-risk haplotypes (H2 or H3). The observed haplotypic association provides the first evidence of the importance of DDAH1 polymorphisms in pre-eclampsia susceptibility.     

Atypical respiratory pathogens

The main atypical pathogens in respiratory tract infections are classified on the basis of their ability to cause atypical pneumonia. This is not a well-defined clinical entity, and it is evident that atypical pathogens can sometimes cause 'typical' pneumonias and vice versa. This emphasizes the need for microbiological diagnosis, since it affects the selection of proper treatment, in which β-lactam antibiotics and aminoglycosides are not effective. Moreover, mixed infections caused by atypical and typical pathogens together are common. At this moment rapid and sensitive diagnostic methods are lacking. Besides numerous viruses, the main bacterial pathogens causing atypical pneumonias are Mycoplasma pneumoniae , two chlamydia species. Chlamydia pneumoniae and C. psittaci , one rickettsia, Coxiella burnetti , and several Legionella species. The majority of these pathogens cause upper respiratory tract infections more often than overt pneumonias. An atypical agent, Chlamydia pneumoniae , has also been associated with chronic inflammatory conditions in the cardiovascular system. The most recently discovered pathogen in atypical pneumonias is a hantavirus causing hantavirus pulmonary syndrome.     

Training effects of cross-country skiing and running on maximal aerobic cycle performance and on blood lipids

Summary Two experiments were carried out to compare the cardiorespiratory and metabolic effects of cross-country skiing and running training during two successive winters. Forty-year-old men were randomly assigned into skiing (n = 15 in study 1,n = 16 in study 2), running (n = 16 in study 1 andn = 16 in study 2) and control (n = 17 in study 1 andn = 16 in study 2) groups. Three subjects dropped out of the programme. The training lasted 9–10 weeks with 40-min exercise sessions three times each week. The training intensity was controlled at 75%–85% of the maximal oxygen consumption (VO_2max) using portable heart rate metres and the mean heart rate was 156–157 beats·min^–1 in the training groups. In the pooled data of the two studies the mean increase in theVO_2max (in ml·min^–1·kg^–1) on a cycle ergometer was 17% for the skiing group, 13% for the running group and 2% for the control group. The increase inVO_2max was highly significant in the combined exercise group compared to the control group but did not differ significantly between the skiing and running groups. The fasting serum concentrations of lipoproteins and insulin did not change significantly in any of the groups. These results suggested that training by cross-country skiing and running of the same duration and intensity at each session for 9–10 weeks improved equally the cardiorespiratory fitness of untrained middle-aged men.     

Autoimmune polyendocrinopathy – candidosis – ectodermal dystrophy (APECED): autosomal recessive inheritance

A genetic analysis was made of 58 patients and their 42 families with APECED (autoimmune polyendocrinopathy--candidosis--ectodermal dystrophy). APECED is characterized by hypoparathyroidism, primary adrenocortical failure and chronic mucocutaneous candidosis, but none of its components is constant. Other endocrine deficiencies can occur as well and also dystrophy of dental enamel and nails. The proportion of affected siblings was 0.147 +/- 0.034 (S.D.) when corrected for truncate single ascertainment, 0.246 +/- 0.019 when corrected for a priori truncate complete ascertainment and 0.240 +/- 0.047 when corrected for a posteriori truncate complete ascertainment. The male/female ratio was 1.04. The results are compatible with autosomal recessive transmission. No heterozygous manifestations of the gene were found. The gene is enriched in isolated subpopulations in central and eastern Finland. APECED is part of the "Finnish heritage of disease".     

Relationship of angiotensin-converting enzyme gene polymorphism to carotid wall thickness in middle-aged men

The insertion/deletion (I/D) polymorphism of the human angiotensin-converting enzyme (ACE) gene is a major determinant of circulating ACE levels. The D allele has been suggested to be a potent risk factor for coronary artery disease; however, the effect of the ACE gene on carotid atherosclerosis remains controversial. We therefore studied the relationship between the ACE gene I/D polymorphism and carotid artery intima-media thickness (IMT). A random sample of 300 men aged 50-59 years living in southern Finland were selected, and 233 agreed to participate (74%). Data were collected in 219 subjects. Quantitative B-mode ultrasonography was used to measure the maximum near and far wall IMT of right and left common, bifurcation, and internal carotid artery. The mean maximum IMT (overall mean) was calculated as the mean of 12 maximum IMTs at 12 standard sites. Patients with an IMT higher than 1.7 mm in at least one of 12 standard sites were assumed to have carotid atherosclerosis. The I/D polymorphism was determined by polymerase chain reaction. Overestimation of the frequency of the DD genotype was eliminated by insertion-specific primer and the inclusion of 5% dimethylsulfoxide. No significant differences were found in carotid wall thickness between the three genotypes; the overall mean IMT were 1.18 +/- 0.30, 1.22 +/- 0.24, and 1.08 +/- 0.40 mm in genotypes of II, ID, and DD, respectively. Similarly, the ACE genotypes and allele frequencies did not differ significantly between the subjects with and those without carotid atherosclerosis. There was no association in the subgroups among only nonsmoking subjects or subjects without chronic medication. The present data indicate that the I/D polymorphism of the ACE gene is not related to carotid IMT and is unlikely to play a major role in carotid atherosclerosis.