Comparison of nucleotide sequences of ribosomal DNA of the mosquito genera Aedes and Ochlerotatus (Diptera: Culicidae: Aedini)

Morphological study allowed identifying 9 species of mosquitoes of the genus Ochlerotatus and 2 species of the genus Aedes. Sequencing of the rDNA region was performed for all these speciemens. The sequences of rDNA were the following: A. cinereus -868 bp, A. vexans--889 bp, Och. cantans--803 bp, O. excrucians--801 bp, O. euedes--794 bp, Och. cyprius--777 bp, O. diantaeus--758 bp, O. intrudens--817 bp, Och. punctor--783 bp, O. dorsalis--748 bp, O. species--767 bp. On average, the size of Aedes rDNA fragments exceeds rDNA of Ochlerotatus by 90-100 bp. The sequences are characterized by a high number of insertions and deletions, and also by point substitutions of nucleotides. It is important to notice that interspecific differences include not only different regions of the internal transcribed spacers, but also the conservative site which is represented by the 5.8S gene. Among four substitutions in this gene, one (C/A) represents the difference between Aedes and Ochlerotatus, the next (T/A) distinguishes A. cinereus from Ochlerotatus speciment and A. vexans, and two substitutions (A/C, T/G) testify the similarity between O. dorsalis and O. species and specimens of Aedes. Besides, two more deletions are typical for O. dorsalis and O. species. One deletion is com- mon, it distinguishes them from the other examined species, and another one is typical only for O. dorsalis. When analyzing morphological characteristics and comparing nucleotide rDNA sequences of O. species with the database, the similarity to O. caspius has been revealed. On the whole, phylogenetic relationships among Ochlerotatus species correspond to subdivision into groups based on morphological characters. Probably, examination of the larger number of specimens will change the morphological division into groups.     

Cross-Sectional and Longitudinal Associations of Different Sedentary Behaviors with Cognitive Performance in Older Adults

Background

The deleterious health effects of sedentary behaviors, independent of physical activity, are increasingly being recognized. However, associations with cognitive performance are not known.

Purpose

To estimate the associations between different sedentary behaviors and cognitive performance in healthy older adults.

Methods

Computer use, time spent watching television (TV), time spent reading and habitual physical activity levels were self-reported twice (in 2001 and 2007) by participants in the SUpplémentation en Vitamines et MinérauX (SU.VI.MAX and SU.VI.MAX2) study. Cognitive performance was assessed at follow-up (in 2007–2009) via a battery of 6 neuropsychological tests used to derive verbal memory and executive functioning scores. Analyses (ANCOVA) were performed among 1425 men and 1154 women aged 65.6±4.5 at the time of the neuropsychological evaluation. We estimated mean differences with 95% confidence intervals (95%CI) in cognitive performance across categories of each type of sedentary behavior.

Results

In multivariable cross-sectional models, compared to non-users, participants using the computer for >1 h/day displayed better verbal memory (mean difference = 1.86; 95%CI: 0.95, 2.77) and executive functioning (mean difference = 2.15; 95%CI: 1.22, 3.08). A negative association was also observed between TV viewing and executive functioning. Additionally, participants who increased their computer use by more than 30 min between 2001 and 2007 showed better performance on both verbal memory (mean difference = 1.41; 95%CI: 0.55, 2.27) and executive functioning (mean difference = 1.41; 95%CI: 0.53, 2.28) compared to those who decreased their computer use during that period.

Conclusion

Specific sedentary behaviors are differentially associated with cognitive performance. In contrast to TV viewing, regular computer use may help maintain cognitive function during the aging process.

Clinical Trial Registration

clinicaltrial.gov (number {"type":"clinical-trial","attrs":{"text":"NCT00272428","term_id":"NCT00272428"}}NCT00272428).     

Alcohol Consumption in Midlife and Cognitive Performance Assessed 13 Years Later in the SU.VI.MAX 2 Cohort

Background

Associations between alcohol consumption and cognitive function are discordant and data focusing on midlife exposure are scarce.

Objective

To estimate the association between midlife alcohol consumption and cognitive performance assessed 13 y later while accounting for comorbidities and diet.

Methods

3,088 French middle-aged adults included in the SU.VI.MAX (1994) study with available neuropsychological evaluation 13 y later. Data on alcohol consumption were obtained from repeated 24h dietary records collected in 1994–1996. Cognitive performance was assessed in 2007–2009 via a battery of 6 neuropsychological tests. A composite score was built as the mean of the standardized individual test scores (mean = 50, SD = 10). ANCOVA were performed to estimate mean differences in cognitive performance and 95% confidence intervals (CI).

Results

In women, abstainers displayed lower cognitive scores than did low-to-moderate alcohol drinkers (1 to 2 drinks/day) (mean difference = −1.77; 95% CI: −3.29, −0.25). In men, heavy drinkers (>3 drinks/day) had higher cognitive scores than did low-to-moderate (1 to 3 drinks/day) (mean difference = 1.05; 95% CI: 0.10, 1.99). However, a lower composite cognitive score was detected in male drinkers consuming ≥90 g/d (≈8 drinks/d). A higher proportion of alcohol intake from beer was also associated with lower cognitive scores. These associations remained significant after adjustment for diet, comorbidities and sociodemographic factors.

Conclusion

In men, heavy but not extreme drinking was associated with higher global cognitive scores. Given the known harmful effects of alcohol even in low doses regarding risk of cancer, the study does not provide a basis for modifying current public health messages.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00272428","term_id":"NCT00272428"}}NCT00272428     

Decreased collagen stability as a response to the loss of structural integrity of thyroid cartilage

The thermal behavior, birefringence properties, and the biochemical composition of thyroid cartilage tissues have been studied. The hyaline cartilage, which was visualized as a quasi-isotropic medium, was composed of type II collagen, which did not denature at temperatures up to 100 degrees C. However, in hyaline cartilage digested by trypsin, the denaturation of collagen occured at 60 degrees C. Collagen fibers in the perichondrium were composed of type I and II collagen and formed a highly organized anisotropic structure (birefringence about 4.75 x 10(-3)) with a melting temperature of about 65 degrees C. The temperature of collagen denaturation in perichondrium in the whole system perichondrium-hyaline cartilage increased up to 75 degrees C, indicating the immobilization of perichondrium collagen by the extracellular matrix of the hyaline constituent.     

Do plants have rhodopsin after all? A mystery of plant G protein-coupled signalling

Considerable physiological and biochemical evidence suggests that plants, like animals, widely use intracellular signalling coupled to heterotrimeric G proteins. Yet, the molecular components of this machinery remained elusive until recently. We overview the work carried out during the last two decades, aimed at identification of the plant proteins involved in G protein-coupled signalling. The completion of the sequencing of the Arabidopsis genome now permits to assess whether plants possess signalling and regulatory components of this machinery corresponding to those known from animals.     

The summation properties of the somatosensory system demonstrated via a study of the tactile sensations evoked by an electrical current and by focused ultrasound

Sensational thresholds of the skin of fingers, palm and forearm have been determined in 5 healthy subjects ageing from 20 to 49 years. About 100 summation curves were obtained. Critical duration of the electrical stimuli remained constant in various areas. Critical duration of ultrasonic stimulation increased from fingers to forearm. The data obtained together with those found in literature suggest that critical duration of the stimulus is associated with the diameter of nonmyelin nervous fibers which are affected by the stimulus increasing with the increase in fiber diameter.     

Immunochemical properties of erythrocyte-specific histone H5 in salmonid fishes

Comparative studies have been made on the immunochemical properties of histone H5 in Salmonidae species. High degree of homology between these histones and H5 histone from Oncorhynchus tschawytscha was demonstrated by microcomplement fixation. Properties of H5 histones in fish and birds are discussed.     

New data on the type of structural changes in DNA of simian adenovirus SA7 microinjected into mouse zygotes

The structure of the transgene has been analysed in a new series of experiments on the transfer of adenovirus SA7 DNA into the mice zygotes by microinjection technique. The previous data on SA7 DNA elimination from the genomes of different organs (sceletal muscles, heart, tail) have been confirmed and detailed for the F0 and F1 generations of transgenic animals. The left end of adenoviral genome has been shown to be predominantly transfered after microinjections of SA7 DNA into the mice zygotes.     

Activity, isoenzyme composition, thermostability and molecular weight of peroxidase from intact and virus infected tobacco plant leaves]

The enzyme peroxidase was isolated from the leaves of the tobacco plant Xanthi (intact and infected with weakly (XY) and highly (XT) pathogenic strains of potato X-virus) and partially purified. The original extract (the 30,000 g supernatant) was purified by ammonium sulfate at 30--80% of saturation and by gel filtration through Sephadex G-25 and G-100 in 0.05 M tris-HCl buffer, pH 7.4 containing 17% sucrose. Disc electrophoresis revealed that both intact and infected plants contain 10 isoperoxidases. The electrophoregrams of isoenzymes from infected plants with the Rf values of 0.1, 0.48, 0.53 and 0.59 stained with benzidine produced a more intensive colouring as compared to the corresponding isoenzymes from intact plants. The total enzymatic activity for the plants infected with the XY and XT strains made up to 180% and 240% of that for the intact plants, respectively. The molecular weights of the peroxidase isoenzymes were found to be the same and equal to 40,000. Study of the thermostability at 60 degrees C and pH 7.0 showed that after 90 min the enzyme activity was 12.4% and 5.1% of the original one in intact and infected plants, respectively. The data obtained suggest that the activity, thermostability and synthesis of some peroxidase isoenzymes in tobacco plant leaves are affected by viral infection.