A New Criterion for Shear Wave Elastometric Assessment Using Modulus of Stiffness Difference between Object and Environment.

Ultrasound shear wave elastography is a modern method that is based on measuring the shear wave velocity making it possible to determine stiffness of soft biological tissues at an arbitrary point (point elastography) or to construct a two-dimensional color image with a subsequent point measurement of stiffness (two-dimensional elastography) and therefore to compare the stiffness of an object with a medium or objects with each other. The aim of the study is to develop a new criterion for the comparative assessment of objects with different stiffness during shear wave elastometry: modulus of stiffness difference between object and environment. Materials and Methods: Using the original technology of building two-dimensional color elastogram, point and two-dimensional shear wave elastography were performed using linear sensors on commercial ultrasound scanners: Aixplorer (SuperSonic Imagine, France), Acuson S2000 (Siemens, Germany), and Verasonics acoustic system (Verasonics Inc., USA) with an open architecture to determine the stiffness values of focal inclusions and compare them with each other with the help of a new comparative elastomeric assessment criterion: modulus of stiffness difference between object and environment. First, the accuracy of the scanners under test was compared on a calibrated Elasticity QA Phantom, model 049 (Computerized Imaging Reference Systems Company, USA) with a known stiffness of various inclusions and thereafter on an uncalibrated BP1901 phantom (Blue Phantom, USA) with unknown stiffness of inclusions. The obtained values were compared to determine the influence of subjective factors on the measurement results. Results: To assess the stiffness of the foci and compare the values with each other taking into account the rigidity of the environment, it is proposed to use a new criterion for the comparative assessment - the modulus of stiffness difference between focus and environment, which quantitatively characterizes the difference between these values. According to this criterion, all three ultrasound scanners have been established to show high and comparable accuracy in determining the stiffness of inclusions within the homogeneous medium in the experiments on phantoms. Two-dimensional shear wave elastography has revealed the effect of the control volume size and the correctness of the color scale setting, especially in the heterogeneous objects, on the results of elastometry. Methodological techniques to reduce the influence of subjective factors have also been proposed. Conclusion: The study has showed the possibility of using the modulus of stiffness difference between object and environment as a new criterion for comparative assessment of objects in shear wave elastometry taking into account stiffness of the environment. To reduce operator-dependence, it is necessary to take into consideration both the way of realizing elastometry (point or two-dimensional color elastography) and a number of other methodological factors.

[Telomere length, telomerase activity, stress and aging].

The review is dedicated to analysis of data available at present time concerning possible influence of stress upon telomere lengths and telomerase activity, as well as various ways of counteracting it. Present-day telomerase theory of aging gains a new impetus, shedding light upon the influence of psychological state of humans and their ability to counteract stress, upon the process of aging. It also tends to regard telomere shortening and the decrease in the activity of telomerase as a marker of level of the ability to adapt to both inner and outer influences. Both aging and age-dependent diseases are proved to be substantially retarded not only by the administration of drugs, but also by psychological means, which forms a good way towards healthy longevity. With complete understanding of the impossibility to prevent or even to slow down natural senescence itself, these methods allow to remove causes, which accelerate senescence, and to increase the average human longevity.

Kondo physics in non-local metallic spin transport devices.

The non-local spin-valve is pivotal in spintronics, enabling separation of charge and spin currents, disruptive potential applications and the study of pressing problems in the physics of spin injection and relaxation. Primary among these problems is the perplexing non-monotonicity in the temperature-dependent spin accumulation in non-local ferromagnetic/non-magnetic metal structures, where the spin signal decreases at low temperatures. Here we show that this effect is strongly correlated with the ability of the ferromagnetic to form dilute local magnetic moments in the NM. This we achieve by studying a significantly expanded range of ferromagnetic/non-magnetic combinations. We argue that local moments, formed by ferromagnetic/non-magnetic interdiffusion, suppress the injected spin polarization and diffusion length via a manifestation of the Kondo effect, thus explaining all observations. We further show that this suppression can be completely quenched, even at interfaces that are highly susceptible to the effect, by insertion of a thin non-moment-supporting interlayer.

WITHDRAWN: MS related employment and disease modifying treatment in the German working population: 1994-2009.

Ahead of Print article withdrawn by publisher.

[The factor analysis results of the relationship of socio-demographic, clinical and functional indicators with the likelihood of identifying age-related disorders in the population in North-Western Russia].

By using the method of factor analysis (principal component method) the determinants of disease in elderly and senile patients were searched with an estimate of their influence degree in the population of the North-West Russia. The data from medical records of 712 patients of both sexes aged 59 to 98 years were analyzed. The factor 1 proved to be associated with: marital status, living conditions, family relationships, bad habits, appearance, cough, diet, hearing and vision, laxatives, joint health, ability to move and sleep disturbances. Factor 2 combined diseases of older: cerebral stroke, myocardial infarction, cardiac arrhythmia, diabetes, kidney disease, obesity, thyroid disease, Parkinson's disease, lung disease, anemia, arthritis, osteoporosis, the number of surgeries and joint diseases. The factor 3 was found to self-association ability before and after admission to the assessment of the patients' mental state for MMSE test after admission. It is concluded that the development of age-related (especially the musculoskeletal system pathology) is associated with social characteristics and living conditions of patients, and treatment of the most age-related diseases requires consideration of comorbidity.

[Telomere length in the population of long-lived persons of North-West region of Russia].

Interdisciplinary study of telomere length, polymorphism of genes of renin-angiotensin (ACE) and serotonin (5HTR2A and 5HTTPR) systems in population of aged and old inhabitants of the North-West of Russia was conducted, in their relations to data from clinical and geriatric anamnesis, and psychological functioning. Regular link between telomere length and respondent's age was demonstrated in subgroups of old respondents and long-livers, by method of factor analysis.

[Distribution of serotonin transporter 5-HTTLPR gene polymorphism in population of the North-West of Russia].

Genetic polymorphism of the promotor zone of the gene of serotonin transporter (5HTT) is related to adaptive ability of humans, along with ability of conducting emotional control. Consequently, 5HTT polymorhisms form a constructive model of enhanced resistance to psychoemotional strain in aged humans. The paper is dedicated to tracing back relations between 5HTT polymorphic variants, and psychological characteristics of the long-livers of the North-Western Russia, as well as the geriatric ones.

Towards water compatible MIPs for sensing in aqueous media.

When synthesizing molecularly imprinted polymers (MIPs), a few fundamental principles should be kept in mind. There is a strong correlation between porogen polarity, MIP microenvironment polarity and the imprinting effect itself. The combination of these parameters eventually determines the overall binding behavior of a MIP in a given solvent. In addition, it is shown that MIP binding is strongly influenced by the polarity of the rebinding solvent. Because the use of MIPs in biomedical environments is of considerable interest, it is important that these MIPs perform well in aqueous media. In this article, various approaches are explored towards a water compatible MIP for the target molecule l-nicotine. To this end, the imprinting effect together with the MIP matrix polarity is fine-tuned during MIP synthesis. The binding behavior of the resulting MIPs is evaluated by performing batch rebinding experiments that makes it possible to select the most suitable MIP/non-imprinted polymer couple for future application in aqueous environments. One method to achieve improved compatibility with water is referred to as porogen tuning, in which porogens of varying polarities are used. It is demonstrated that, especially when multiple porogens are mixed, this approach can lead to superior performance in aqueous environments. Another method involves the incorporation of polar or non-polar comonomers in the MIP matrix. It is shown that by carefully selecting these monomers, it is also possible to obtain MIPs, which can selectively bind their target in water.

Epilepsy-related employment prevalence and retirement incidence in the German working population: 1994-2009.

Epilepsy-related employment prevalence and retirement incidence were investigated in the German working population from 1994 to 2009. The overall mean prevalence of employment of people with epilepsy was 5.1±0.2 per 1000 workers. The employment rate among people with epilepsy increased from 63.5% in 1994 to 65.9% in 2000 (0.4% annually) and then more steeply from 66.8% in 2001 to 76.9% in 2009 (1.4% annually). A prominent increase in rate of employment of people with epilepsy since 2001 was temporarily associated with approval of leviteracetam in 2000 (P<0.001, OR=8.3, CI=6.45-10.12). The overall mean employment rate of people with epilepsy was lower than that of the general population (68.5% vs 90.1%, P<0.001). The overall mean incidence of epilepsy-related retirement (RI) during the study was 4.6±1.6/1000, similar to the RI for people with other illnesses (5.1±0.8/1000), and the risk of retiring because of epilepsy was not higher than that for other illnesses over the entire study period (P=0.52, OR=1.11, CI=0.86-1.43). The RI among workers with epilepsy, however, sharply declined from 8.3/1000 in 1994 to 2.9/1000 in 2000 (-65%, < 0.001), followed by a slight increase and stabilization at 3.9/1000 workers between 2001 and 2009. The decline in RI among people with epilepsy was temporarily associated with legislation of the Law on Support of Employment in 1996 (P=0.032, OR=2.15, CI=1.17-2.89) and approval of lamotrigine in 1993 (P=0.024, OR=2.64, CI=2.17-3.88). These patterns suggest that drug treatment and legislative laws may have led to increased employment and reduced retirement rates for people with epilepsy.

[Distribution of structural polymorphisms of angiotensin-converting enzyme and serotonin receptor 5-HT2A genes among long-livers of North-Western Russia].

In the group of long-livers of the North-West of Russia, I/D polymorphism of angiotensin-converting enzyme (ACE) gene and C102T polymorphism of serotonin receptor (5-HT2A) gene were studied. No reliable differences in allele frequency of these genes between long-livers and young people were detected. Nevertheless, highly pronounced difference in the A1/A2 allele frequency of 5-HT2A gene between populations of the North-West of Russia, on the one hand, and of the USA, on the other hand, was discovered (i.e. 0.397(A1), 0.603(A2), and 0.615(A1), 0.385(A2), respectively). Differences of this kind between the two populations deserve special consideration, conditioning the necessity of further detailed analysis of other genes of the serotonin system in the populations of other regions of Russia.

[Polymorphisms of genes of rennin-angiotensine system and their correlation with psychological manifestations of birth stress].

Study of correlation of polymorphisms of genes of the rennin-angiotensine system--insertion-deletion (I/D) polymorphism of the angiotensine-converting enzime (ACE), and the polymorphism of angiotensinogen (AGT), consisting in submission of T into C in the 704 position (M235T)--with various characteristics of psychological functioning and clinical characteristics in women giving birth, was conducted. The group consisted of 56 young female Ss, without chronic diseases in the anamnesis, no complication in the course of pregnancy, birth normal and timely, state of the child normal in all cases. Basing on factor analysis of 7 psychological induces, providing integral assessment of state of the Ss in the course la late pregnancy, giving birth, and the immediately following post partum period, statistically reliable correlation between such first-rate psychological process as creativity, and polymorphism of the gene of angiotensinogene, was demonstrated, as well as difference in distribution of genotypes between the group of women giving birth, and general population. Statistically relevant correlation between presence of the deletion (D) allele of the ACE gene, and heightened level of neuroticization, reported by us earlier, was observed in this case, as well. No significant links between religiosity/spirituality, and genetic data was found. These results are in concordance with present-day views concerning the role of the rennin-angiotensine system in the providing of active adaptation to stressful conditions; they tend to provide fresh outlook upon the comparative study of input of heredity, and education, into the ontogenesis of higher psychological functions in normal humans.

[Possible correlation of polymorphism of angiotensin-converting enzyme gene with psychological aspects of birth stress].

The paper presents results of a pilot study of genetic correlates of adaptive strategies characteristic for religious and (or) spiritual people in stress, induced by unusual and (or) extreme conditions. Birth stress, experienced by 79 young normal female urban dwellers Ss in the course of late pregnancy, giving birth, and the immediately following period post partum, was chosen as model of stress in general. Their state, as well as the state of the child, was monitored in each case by professional physicians, and assessed according to standard obstetric procedures. 3 kinds of standard psychological tests, providing assessment of neurotization, creativity, and the scope of religious/spiritual sensations, were conducted. The latter formed focal point of our research. As in has recently been supposed, religious/spiritual people tend to be more adaptive in illness and stress, which is quite important for clinical practice. The first aim of our study was to test whether religious/spiritual sensations in stress tend to occur as part of general neurotization; or, as part of creative response in the service of the ego; or, finally, they form a specific dimension of adaptive strategies. In home to simultaneously assess possible genetic determination of each of these options, we have introduced intro our study a module of assessment of genetic I/D polymorphisms of ACE gene, primarily linked to the status of the renin-angiotensin system. As a result of factor analysis, existence of 3 strong trends was demonstrated. 1. Neurotization, creativity, religious/spiritual processes tend to form 3 independent aspects of response of normal humans to birth stress. 2. Frequency of occurrence of D-allele tends to reveal strong correlation with only one of these 3 options, which is the generall level of neurotization. The latter conclusion corresponds well to what is currently known about the role of renin-angiotensin system primarily in regulation of cardiovascular system, and probably adaptation to stress. 3. Frequency of occurrence of D-allele in the mother tends to reveal inverse correlation with the Apgar index of the child (assessment of its physiological state in the course of the first several minutes after birth, based upon such characteristics as heart beat rate, ability to independent breathing, state of the skin, etc.), and is not linked to usual standard biometric parameters of newborn children. Continuing to work on this model, we intend to formally assess possible impact of heredity via other genes upon psychological, especially religious and spiritual aspects of adaptation to stress of women in birth; and also approach to possible genetic correlates of the state of newborn children.

Systematic study of steric and spatial contributions to molecular recognition by non-covalent imprinted polymers.

Although molecular imprinting is a widely accepted method for producing template specific polymers, the general rules for prediction and control of the binding and catalytic properties of these materials are still not fully understood. One reason for this is the problematic structural analysis of the active sites in the polymers, which are not amenable to X-ray crystallography or microscopic techniques due to their amorphous and heterogeneous nature. Therefore, molecular probes have been the most informative agents for the analysis of the structure of active sites. This paper focuses on the steric and geometrical aspects of shape recognition in non-covalent imprinted polymers, with particular effort to minimize other factors contributing to molecular recognition by the polymers. Chiral amine compounds with systematic changes in spatial, distal and conformational components of sterically controlled molecular recognition were investigated for use as non-covalent imprinted polymers. Chromatographic studies revealed that steric and spatial interactions influence the selectivity properties of imprinted polymers in a predictable fashion.

Development of an aspartic acid-based cross-linking monomer for improved bioseparations.

Improved specificity and binding affinity by molecularly imprinted polymers is possible by development of novel functional materials. Furthermore, increasing the cross-link density of imprinted polymers by using cross-linking functional groups was anticipated to improve polymer molecular recognition. A novel cross-linking monomer derived from an L-aspartic acid precursor was synthesized and employed in molecularly imprinted polymers to mimic more closely the scaffolding of proteins, and thus provide more protein-like selectivity. Chromatographic results revealed a more than 7-fold improvement in polymers imprinted using the new monomer versus a traditionally formulated polymer imprinted with methacrylic acid as the functional monomer.

An analysis of the morbidity and mortality of short-bowel syndrome in the pediatric age group.

Twenty-two children with short-bowel syndrome (SBS) were treated at the C. S. Mott Children's Hospital in the University of Michigan Medical Center between June 1983 and May 1993. Definition of SBS was loss of 70% or more of the total small bowel. Seventeen of these children are currently alive, a 77% survival rate. Patients were followed for a mean of 1,148 days. The mean age of SBS development was 71 days of life. The only predictive indicator of patient survival was direct bilirubin levels. Sixty-seven percent of the children died if they had a direct bilirubin of > 4 mg/dl > or = 6 months duration.

A comparison of flexible and constrained haptens in eliciting antibody catalysts for paraoxon hydrolysis.

A new amine-oxide hapten was employed as an antigen, producing seven monoclonal antibodies (mAbs) from a panel of 20 that catalyzed paraoxon hydrolysis. The current hapten design differs from that previously described in that the molecule is inherently more flexible than its constrained predecessor. One of the seven antibody catalysts, mAb 1H9, showed the highest activity and was selected for detailed study. At pH = 8.77, the catalytic hydrolysis of paraoxon by mAb 1H9 followed Michaelis Menten kinetics affording a k(cat) = 3.73 x 10(-4) min(-1) and a Km = 1.12 mM with a rate acceleration k(cat)/k(uncat) = 56. The hapten was found to be a competitive inhibitor of antibody-catalyzed paraoxon hydrolysis with a Ki = 0.54 mM. A comparison of both the number and proficiency of antibody catalysts obtained when utilizing a flexible versus constrained hapten indicates that, for paraoxon hydrolysis, constrained haptens elicit superior catalysts, suggesting that further development should begin with the use of constrained haptens in producing more proficient antibody catalysts for paraoxon hydrolysis.