Haplotype distribution of five nuclear genes based on network genealogies and Bayesian inference indicates that Trypanosoma cruzi hybrid strains are polyphyletic

Chagas disease is still a major public health problem in Latin America. Its causative agent, Trypanosoma cruzi, can be typed into three major groups, T. cruzi I, T. cruzi II and hybrids. These groups each have specific genetic characteristics and epidemiological distributions. Several highly virulent strains are found in the hybrid group; their origin is still a matter of debate. The null hypothesis is that the hybrids are of polyphyletic origin, evolving independently from various hybridization events. The alternative hypothesis is that all extant hybrid strains originated from a single hybridization event. We sequenced both alleles of genes encoding EF-1 alpha, actin and SSU rDNA of 26 T. cruzi strains and DHFR-TS and TR of 12 strains. This information was used for network genealogy analysis and Bayesian phylogenies. We found T. cruzi I and T. cruzi II to be monophyletic and that all hybrids had different combinations of T. cruzi I and T. cruzi II haplotypes plus hybrid-specific haplotypes. Bootstrap values (networks) and posterior probabilities (Bayesian phylogenies) of clades supporting the monophyly of hybrids were far below the 95% confidence interval, indicating that the hybrid group is polyphyletic. We hypothesize that T. cruzi I and T. cruzi II are two different species and that the hybrids are extant representatives of independent events of genome hybridization, which sporadically have sufficient fitness to impact on the epidemiology of Chagas disease.

Simultaneous flow injection preconcentration of lead and cadmium using cloud point extraction and determination by atomic absorption spectrometry

A flow injection (FI) micelle-mediated separation/preconcentration procedure for the determination of lead and cadmium by flame atomic absorption spectrometry (FAAS) has been proposed. The analytes reacted with 1-(2-thiazolylazo)-2-naphthol (TAN) to form hydrophobic chelates, which were extracted into the micelles of 0.05% (w/v) Triton X-114 in a solution buffered at pH 8.4. In the preconcentration stage, the micellar solution was continuously injected into a flow system with four mini-columns packed with cotton, glass wool. or TNT compresses for phase separation. The analytes-containing micelles were eluted from the mini-columns by a stream of 3 mol L(-1) HCl solution and the analytes were determined by FAAS. Chemical and flow variables affecting the preconcentration of the analytes were studied. For 15 mL. of preconcentrated solution, the enhancement factors varied between 15.1 and 20.3, the limits of detection were approximately 4.5 and 0.75 mu g L(-1) for lead and cadmium, respectively. For a solution containing 100 and 10 mu g L(-1) of lead and cadmium, respectively, the R.S.D. values varied from 1.6 to 3.2% (n = 7). The accuracy of the preconcentration system was evaluated by recovery measurements on spiked water samples. The method was susceptible to matrix effects, but these interferences were minimized by adding barium ions as masking agent in the sample solutions, and recoveries from spiked sample varied in the range of 95.1-107.3%. (C) 2008 Elsevier B.V. All rights reserved.

An expert flow system involving in-line prior assay for turbidimetric determination of chloride and sulphate in natural waters

A multi-pumping flow system exploiting prior assay is proposed for sequential turbidimetric determination of sulphate and chloride in natural waters. Both methods are implemented in the same manifold that provides facilities for: in-line sample clean-up with a Bio-Rex 70 mini-column with fluidized beads: addition of low amounts of sulphate or chloride ions to the reaction medium for improving supersaturation; analyte precipitation with Ba(2+) or Ag(+); real-time decision on the need for next assay. The sample is initially run for chloride determination, and the analytical signal is compared with a preset value. If higher, the sample is run again, now for sulphate determination. The strategy may lead to all increased sample throughput. The proposed system is computer-controlled and presents enhanced figures of merit. About 10 samples are run per hour (about 60 measurements) and results are reproducible and Unaffected by the presence of potential interfering ions at concentration levels usually found in natural waters. Accuracy was assessed against ion chromatography. (C) 2008 Elsevier B.V. All rights reserved.

Participation of kinin receptors on memory impairment after chronic infusion of human amyloid-beta 1-40 peptide in mice

Chronic infusion of human amyloid-beta 1-40 (A beta) in the lateral ventricle (LV) of rats is associated with memory impairment and increase of kinin receptors in cortical and hippocampal areas. Deletion of kinin B1 or B2 receptors abolished memory impairment caused by an acute single injection of A beta in the LV. As brain tissue and kinin receptors could unlikely react to acute or chronic administration of a similar quantity of A beta, we evaluated the participation of B1 or B2 receptors in memory impairment after chronic infusion of A beta. Male C57BI/6 J (wt), knock-out B1 (koB1) or B2 (koB2) mice (12 weeks of age) previously trained in a two-way shuttle-box and achieving conditioned avoidance responses (CAR, % of 50 trials) were infused with AB (550 pmol, 0.12 mu L/h, 28 days) or vehicle in the LV using a mini-osmotic pump. They were tested before the surgery (TO), 7 and 35 days after the infusion started (T7; T35). In T0, no difference was observed between CAR of the control (Cwt = 59.7 +/- 6.7%; CkoB1 = 46.7 +/- 4.0%; CkoB2 = 64.4 +/- 5.8%) and A beta (A beta wt = 66.0 +/- 3.0%; A beta koB1 = 66.8 +/- 8.2%; A beta koB2 = 58.7 +/- 5.9%) groups. In T7, A beta koB2 showed a significant decrease in CAR (41.0 +/- 8.6%) compared to the control-koB2 (72.8 +/- 2.2%, P <0.05). In T35, a significant decrease (P <0.05) was observed in A beta wt (40.7 +/- 3.3%) and A beta koB2 (41.2 +/- 10.7%) but not in the A beta koB1 (64.0 +/- 14.0%) compared to their control groups. No changes were observed in the controls at T35. We suggest that in chronic infusion of BA, B1 receptors could playan important role in the neurodegenerative process. Conversely, the premature memory impairment of koB2 suggests that it may be a protective factor. (C) 2009 Elsevier Ltd. All rights reserved.

The accuracy of the Clock Drawing Test compared to that of standard screening tests for Alzheimer`s disease: results from a study of Brazilian elderly with heterogeneous educational backgrounds

Background: Although the Clock Drawing Test (CDT) is the second most used test in the world for the screening of dementia, there is still debate over its sensitivity specificity, application and interpretation in dementia diagnosis. This study has three main aims: to evaluate the sensitivity and specificity of the CDT in a sample composed of older adults with Alzheimer`s disease (AD) and normal controls; to compare CDT accuracy to the that of the Mini-mental State Examination (MMSE) and the Cambridge Cognitive Examination (CAMCOG), and to test whether the association of the MMSE with the CDT leads to higher or comparable accuracy as that reported for the CAMCOG. Methods: Cross-sectional assessment was carried out for 121 AD and 99 elderly controls with heterogeneous educational levels from a geriatric outpatient clinic who completed the Cambridge Examination for Mental Disorder of the Elderly (CAMDEX). The CDT was evaluated according to the Shulman, Mendez and Sunderland scales. Results: The CDT showed high sensitivity and specificity. There were significant correlations between the CDT and the MMSE (0.700-0.730; p < 0.001) and between the CDT and the CAMCOG (0.753-0.779; p < 0.001). The combination of the CDT with the MMSE improved sensitivity and specificity (SE = 89.2-90%; SP = 71.7-79.8%). Subgroup analysis indicated that for elderly people with lower education, sensitivity and specificity were both adequate and high. Conclusions: The CDT is a robust screening test when compared with the MMSE or the CAMCOG, independent of the scale used for its interpretation. The combination with the MMSE improves its performance significantly, becoming equivalent to the CAMCOG.

Temporomandibular Disorder in Brazilian Patients: A Preliminary Study

The objective of the current study was to evaluate disease-related beliefs, adherence to treatment, quality of life, coping strategies and cognitive status in a group of Brazilian patients with Temporomandibular Disorder (TMD). Thirty patients were evaluated with a semi-directed interview, the Coping Strategies Inventory, and a Mini-Mental State Examination. Although half (50%) of the patients had known their diagnosis long term, 40% of the sample were not correctly following proposed treatment. All patients had a similar pattern of pain behavior related to TMD, while disease-related beliefs, quality of life and coping strategies were variable. Expectations about treatment also had significant association with treatment adherence. The findings of this study suggest that a more thorough understanding of individual differences in TMD is warranted.

Stress and coping in older people with Alzheimer`s disease

To investigate stress intensity and coping style in older people with mild Alzheimer`s disease. The potential risk assessment of a stress event and the devising of coping strategies are dependent on cognitive function. Although older individuals with Alzheimer`s disease present significant cognitive impairment, little is known about how these individuals experience stress events and select coping strategies in stress situations. Survey. A convenient sample of 30 cognitively healthy older people and 30 individuals with mild Alzheimer`s disease were given an assessment battery of stress indicators (Symptom Stress List, Cornell Scale for Depression in Dementia, State-Trait Anxiety Inventory), coping style (Jalowiec Coping Scale) and cognitive performance (mini-mental state exam) were applied in both groups. Statistical analysis of the data employed the Mann-Whitney test to compare medians of stress indicators and coping style, Fischer`s exact test to compare proportions when expected frequencies were lower than five, and Spearman`s correlation coefficient to verify correlation between coping style and cognitive performance. Both groups suffered from the same stress intensity (p = 0.254). Regarding coping styles, although differences were not statistically significant (p = 0.124), emotion-oriented coping was predominant in the patients with Alzheimer`s disease. However, those individuals displaying better cognitive performance in the Alzheimer`s disease group had selected coping strategies focused on problem solving (p = 0.0074). Despite a tendency for older people with Alzheimer`s disease to select escape strategies and emotional control, rather than attempting to resolve or lesser the consequences arising from a problem, coping ultimately depends on cognitive performance of the individual. The findings of this study provide information and data to assist planning of appropriate support care for individuals with Alzheimer`s disease who experience stress situations, based on their cognitive performance.

Cognitive impairment in cancer pain patients receiving opioids

This study aimed to compare cognitive function of cancer pain patients being given opioids during their cancer treatment (n = 14) with that of patients receiving treatment without opioids (n = 12). Correlations between cognitive function, pain intensity, and opioid dose were analyzed. Patients were assessed 3 times in a I-month period, using the Trail-Making Test, Mini-Mental State Examination, Digit Span, and Brief Cognitive Screening Battery. Opioid use was not associated with clear cognitive impairment. Patients being treated without opioids did perform better in the Digit Span Test reverse-order test (P = .029) and the clock drawing test (P = .023), but the differences arose in just I assessment in each case. Pain intensity correlated negatively with scores in the Mini-Mental State Examination (P = .001) and some Brief Cognitive Screening Battery tests (incidental recall, immediate recall, and late recall; P <= .042) in the group receiving opioids. Opioid dose did not correlate with any of the measures of cognitive performance. However, the patients with the worst performance scores were those with more severe pain. Further studies are needed to clearly distinguish between the effects of opioids versus the effects of pain.

Relationship Between Cortisol Levels and Memory Performance may be Modulated by the Presence or Absence of Cognitive Impairment: Evidence from Healthy Elderly, Mild Cognitive Impairment and Alzheimer`s Disease Subjects

An inverted U-shape function between cortisol levels and memory performance has been reported in studies on both young animals and humans. Yet little is known about this relationship in normal aging or in older subjects with cognitive impairment. This issue is particularly significant since increased levels of cortisol have been reported in Alzheimer`s disease (AD). The present study examined the association between cortisol levels and visual memory performance in healthy subjects as well as in individuals presenting mild cognitive impairment (MCI) or AD. Salivary cortisol was measured in 40 healthy elderly subjects, 31 individuals with amnestic MCI, and 40 subjects with mild probable AD. Memory performance was evaluated using the Brief Cognitive Screening Battery. Higher cortisol levels were associated with better memory performance in healthy elderly (p = 0.005), while higher cortisol levels were correlated with poorer memory performance in MCI subjects (p = 0.011). No correlation between cortisol and memory was found in the AD group (p > 0.05). These results suggest that the relationship between cortisol levels and memory performance in the aging process could vary according to the presence or absence of cognitive impairment.

Possible Relationship Between Performance and Oxidative Stress in Endurance Horses

The purpose of this study was to evaluate oxidative stress, antioxidant biomarkers, and performance during a multiday 210-km endurance race. Nine endurance athlete horses participated in this study. Samples were always taken at the same times of day, before the beginning of the race and after every day of competition. Analytic measurements included glutathione reductase (GR) and catalase activity, thiobarbituric acid-reactive substances (TBARs), and reactive carbonylated derivatives. Competition intensity was low, with an average speed of 12.56 +/- 0.9 km/h. Four horses were unable to finish the race because of metabolic problems or fatigue. GR activity increased progressively (P < .001) throughout the competition, and TBARs showed a significant rise compared with baseline values (P < .01) but remained at the same levels throughout the 3 days of competition. Catalase and reactive carbonylated derivatives did not show any significant alterations in any time period. The best performance was obtained from horses who demonstrated higher GR capacity and/or lower TBAR concentration. In conclusion, redox. status seems to modulate horses` performance in endurance races, but further Studies are needed to better determine the adequate oxidant/antioxidant ratio to acquire optimal performance.

Assessment of Depressive Symptoms and Cognitive Impairment in Elders From Rural Areas of the Brazilian State of Rio Grande do Sul

The main objective of this study was to examine the relationships among demographic characteristics, depressive symptoms, and cognitive impairment in oldest-old elders from rural areas of the Brazilian State of Rio Grande do Sul. A cross-sectional, descriptive correlational design was used to conduct the study. 137 Brazilian elders age 80 years or over. A target population data form, a county data form, a demographic questionnaire, the Mini-Mental State Examination, and the Depressive Cognition Scale were used to collect the data. A significant difference was found between males and females in regard to cognitive impairment. In addition, educational level and depressive symptoms were correlated with cognitive impairment. Depressive symptoms were a weak but significant predictor of cognitive impairment after controlling for the effect of age, gender, and educational level of the oldest-old elders. The findings need to be interpreted cautiously since the sample scored above the cutoff points for cognitive impairment, and had low scores on depressive symptoms. Despite several limitations, findings from this study can be a foundation for further studies, and well-designed correlational or experimental approaches, are warranted.

Effect of Amblyomma cajennense Ticks on the Immune Response of BALB/c Mice and Horses

This work evaluated the effect of the Amblyomma cajennense tick on the immune response of BALB/c mice and on horse lymph node cell proliferation. We observed that mice do not develop resistance to nymphs of this tick species and that lymphocyte proliferation of this host is inhibited by tick saliva, nymphal extract, or infestations. Horse lymph node cell proliferation is inhibited by tick saliva as well. Mice lymphocytes under the effect of tick saliva, nymphal extract, or infestations display a predominantly. p Th-2 cytokine production pattern. Observed results partially explain this tick`s disease vectoring capacity and broad host range.

Influence of ammonium sulphate feeding time on fed-batch Arthrospira (Spirulina) platensis cultivation and biomass composition with and without pH control

Previous work demonstrated that a mixture of NH(4)Cl and KNO(3) as nitrogen source was beneficial to fed-batch Arthrospira (Spirulina) platensis cultivation, in terms of either lower costs or higher cell concentration. On the basis of those results, this study focused on the use of a cheaper nitrogen source mixture, namely (NH(4))(2)SO(4) plus NaNO(3), varying the ammonium feeding time (T = 7-15 days), either controlling the pH by CO(2) addition or not. A. platensis was cultivated in mini-tanks at 30 degrees C, 156 mu mol photons m(-2) s(-1), and starting cell concentration of 400 mg L(-1), on a modified Schlosser medium. T = 13 days under pH control were selected as optimum conditions, ensuring the best results in terms of biomass production (maximum cell concentration of 2911 mg L(-1), cell productivity of 179 mg L(-1) d(-1) and specific growth rate of 0.77 d(-1)) and satisfactory protein and lipid contents (around 30% each). (C) 2011 Elsevier Ltd. All rights reserved.

Prevalence of Alcohol-Related Problems in an Elderly Population and Their Association With Cognitive Impairment and Dementia

Background: Studies investigating the association between alcohol use and cognitive disorders in the elderly population have produced divergent results. Moreover, the role of alcohol in cognitive dysfunction is not clear. The aims of this study were to estimate the prevalence of alcohol-related problems in an elderly population from Brazil and to investigate their association with cognitive and functional impairment (CFI) and dementia. Methods: A community-based cross-sectional study was performed. A sample of 1,145 elderly people was examined in 2 phases. Several instruments were utilized in the first phase: the CAGE questionnaire was used to identify potential cases of alcohol-related problems, and a screening test for dementia was used to estimate CFI. The CAMDEX interview (Cambridge Examination) and DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition) criteria were used for the clinical diagnosis of dementia in the second phase. Results: ""Heavy alcohol use"" (CAGE >= 2) was found in 92 subjects (prevalence: 8.2%). It was associated with gender (males, p < 0.001), low education (only in females, p = 0.002), and low socioeconomic level (p = 0.001, in females; p = 0.002, in males). The Mini Mental State Examination exhibited a nonlinear relationship with alcohol-related problems in females; ""mild-moderate alcohol use"" (CAGE < 2) presented the highest score. A significant association between alcohol-related problems and cognitive dysfunction was found only in females. ""Heavy alcohol use"" was associated with higher CFI and dementia rates compared to ""mild-moderate alcohol use"" (p = 0.003 and p < 0.001, respectively). ""Mild-moderate alcohol use"" had a tendency of association with lower CFI and dementia rates when compared to ""no alcohol use"" (p = 0.063 and 0.050, respectively). Conclusion: Our findings suggest that alcohol use does not have a linear relationship with cognitive decline.

Improving Alzheimer`s Disease Diagnosis with Machine Learning Techniques

There is not a specific test to diagnose Alzheimer`s disease (AD). Its diagnosis should be based upon clinical history, neuropsychological and laboratory tests, neuroimaging and electroencephalography (EEG). Therefore, new approaches are necessary to enable earlier and more accurate diagnosis and to follow treatment results. In this study we used a Machine Learning (ML) technique, named Support Vector Machine (SVM), to search patterns in EEG epochs to differentiate AD patients from controls. As a result, we developed a quantitative EEG (qEEG) processing method for automatic differentiation of patients with AD from normal individuals, as a complement to the diagnosis of probable dementia. We studied EEGs from 19 normal subjects (14 females/5 males, mean age 71.6 years) and 16 probable mild to moderate symptoms AD patients (14 females/2 males, mean age 73.4 years. The results obtained from analysis of EEG epochs were accuracy 79.9% and sensitivity 83.2%. The analysis considering the diagnosis of each individual patient reached 87.0% accuracy and 91.7% sensitivity.