Formation of Hydroxyapatite-Based Hybrid Materials in the Presence of Platelet-Poor Plasma Additive.

Biomaterials based on hydroxyapatite with controllable composition and properties are promising in the field of regenerative bone replacement. One approach to regulate the phase composition of the materials is the introduction of biopolymer-based additives into the synthesis process. The purpose of present study was to investigate the formation of hydroxyapatite-based hybrid materials in the presence of 6-24% platelet-poor plasma (PPP) additive, at a [Ca]/[PO] ratio of 1.

A review on the synthesis and properties of hydroxyapatite for biomedical applications.

Hydroxyapatite (HA or HAp) is one of the most preferred biomaterials, specifically for bone tissue engineering. HAp is available naturally and is also chemically synthesized. The properties, shape, size and crystalline structure and applications of HAp vary widely depending on the source and extraction methods used.

Method and Computer System for Dialog Optimization of Aging Biomarker Panels for Biological Age Assessment.

A concept, method, algorithm, and computer system (CS) of step-by-step dialog optimization of biomarker (BM) panels for assessing human biological age (BA) according to a number of universal criteria based on incomplete and noisy data have been developed. This system provides the ability to automatically build BM panels for BA assessment and to increase the accuracy of BA determination while reducing the number of measured BMs. The optimization criteria are as follows: high correlation of BMs with chronological age (CA); minimum size of BM panels, obtained by rejecting highly cross-correlated BMs; high accuracy of BA assessment; high accuracy of BA/CA dependency interpolation; absence of outliers in BM values, which reduce the BA assessment accuracy; rejection of panels resulting in a high standard deviation for the BA-CA difference; and possible additional criteria entered by the researcher according to the task specifics.

Decrease in Human Aging Rate Since the Middle of the 20th Century.

The plot of the mortality rate minus the constant A of the Gompertz-Makeham equation and the plot of the mortality intensity increment d(m) reflect the actual rate of biological aging. It was shown that since the middle of the 20th century there has been a slowdown in aging for all the countries of the world that were studied (for available periods in the history), in all parameters: R and k coefficients of the Gompertz equation, mortality intensity increment d(m) and maximum life span. The slowdown in the aging rate of continues to the present.

Historical Evolution of Old-Age Mortality and New Approaches to Mortality Forecasting.

Knowledge of future mortality levels and trends is important for actuarial practice but poses a challenge to actuaries and demographers. The Lee-Carter method, currently used for mortality forecasting, is based on the assumption that the historical evolution of mortality at all age groups is driven by one factor only. This approach cannot capture an additive manner of mortality decline observed before the 1960s.

Mortality Trajectories at Exceptionally High Ages: A Study of Supercentenarians.

The growing number of persons surviving to age 100 years and beyond raises questions about the shape of mortality trajectories at exceptionally high ages, and this problem may become significant for actuaries in the near future. However, such studies are scarce because of the difficulties in obtaining reliable age estimates at exceptionally high ages. The current view about mortality beyond age 110 years suggests that death rates do not grow with age and are virtually flat.

Natural aging as as a sequential poly-systemic syndrome.

We review the progression of aging as a sequential development of multiple syndromes analogous to other diseases. This generalized approach may allow practicing physicians to consider the signs of aging as manifestations of a poly-syndrome disease and facilitate prevention, diagnosis and treatment of common aging-related dysfunctions.

How regularities of mortality statistics explain why we age despite having potentially ageless somatic stem cells.

Researchers working in the area of ageing have found numerous manifestations of this process at the molecular biological level, including DNA and protein damage, accumulation of metabolic by-products, lipids peroxidation, macromolecular cross-linking, non-enzymatic glycosylation, anti-oxidant/pro-oxidant misbalance, rising of pro-inflammatory cytokines, etc. This results in an increase in the proportion of cells in growth arrest, reduction of the rate of information processing, metabolic rate decrease, and decrease in rates of other processes characterizing dynamic aspects of the organism's interaction with its environment. Such staggering multilevel diversity in manifestation of senescence precludes (without methodology of systems biology) development of a correct understanding of its primary causes and does not allow for developing approaches capable of postponing ageing or reducing organisms' ageing rate to attain health preservation.

The Future of Human Longevity.

Recent scientific publications suggest that human longevity records stopped increasing. Our finding that the mortality of centenarians has not decreased noticeably in recent decades (despite a significant mortality decline in younger age groups) is consistent with this suggestion. However, there is no convincing evidence that we have reached the limit of human life span.

Effect of Alpha-Fetoprotein on Lifespan of Old Mice.

Alpha-fetoprotein (AFP) is one of the best-known embryo-specific proteins. It is used to diagnose fetal abnormalities and tumors of the gastrointestinal tract and liver. AFP has pronounced immunotropic and detoxifying effect and a direct apoptotic effect on tumor cells.

Developing criteria for evaluation of geroprotectors as a key stage toward translation to the clinic.

In the coming decades, a massive shift in the aging segment of the population will have major social and economic consequences around the world. One way to offset this increase is to expedite the development of geroprotectors, substances that slow aging, repair age-associated damage and extend healthy lifespan, or healthspan. While over 200 geroprotectors are now reported in model organisms and some are in human use for specific disease indications, the path toward determining whether they affect aging in humans remains obscure.

Early Thymus Involution--Manifestation of an Aging Program or a Program of Development?

"I see no physical reason why it should not have been possible for life to construct ageless individuals", said Carl von Weizsacker in 1979 at the Conference on DNA. An obvious biological reason for senescence may be the action of a built-in aging program. Many gerontologists believe that early thymic involution is an argument in favor of the existence of such a program.

[Biological Age as a Method for Systematic Assessment of Ontogenetic Changes in the State of an Organism].

Aging is a common feature of living and nonliving systems as a disturbance of the structure of the system accumulating with age. The only cause of aging of a living system, which is capable of renewal, is the insufficiency of renewal. The latter manifests itself as two global mechanisms of aging: the genetically determined nonrenewal of a number of structures that can only die with age (stochastic aging) and the regulatory reduction in the rate of self-renewal of living structures.

[Biological age as an index of human health level, aging and ecological well-being].

Methodology of estimating the integral health and aging level is based on the system index of biological age (BA). The paper introduces the reader to the BA principles and structure, search for meaningful aging biomarkers, useful tests, and applications in present-day biomedicine. The concept of BA is directly linked with the theory of organism vitality.

[Enhancement of electrocardiogram information capability by identification of the ECG spectrum phases].

The authors discuss feasibility to extract additional information about electrical activity of the heart from the ECG magnitude and phase spectrum. Fifty digitized ECG fragments from the MIT-BIH Arrhythmia Database and PhysioBank ECG repository data were analyzed. It was shown that ECG phase harmonics contains valuable information about the ECG signal that can be used eventually for the development of advanced ECG analysis tools.

[The system theory of aging: methodological principles, basic tenets and applications].

The paper deals with the system theory of aging constructed on the basis of present-day scientific methodology--the system approach. The fundamental cause for aging is discrete existence of individual life forms, i.e.

[Prognosis of individual survival in animals with fatal and non-fatal tumors].

Cohort analysis of life span in a uniform LIO rat population established a correlation between death cause and age-related death force parameters. It also demonstrated certain sex-related differences involved. The life span of males which had tumors at the time of death, whatever the real cause of death, was significantly longer than that in tumor-free animals.