The role of age-related and adaptive changes in the vascular wall in atherogenesis in light of the theory of Academician I. V. Davydovski? on atherosclerosis

Aorta and coronary arteries (1053 and 386 cases, respectively) were evaluated in young persons. It is shown that atherosclerotic developments in the vessels are largely determined by hyperplastic involvement of the intima due to age-related vascular rearrangement and the hemodynamic factor. For aorta, these are represented by rhythmic structures which seem to give rise to the majority of the fibrous plaques. The findings are in consistence with I. V. Davydovsky's conceptions on age-related and adaptation changes in the vascular wall emerging during various human vital activities and supposed to underlie the development of atherosclerosis.     

Changes in myocardial enzyme activity of patients with dilated cardiomyopathy and the relationship of these parameters to disturbed myocardial contractility and coronary atherosclerosis]

Endomyocardial biopsies from 20 patients with dilated cardiomyopathy (DCMP) were studied histochemically. The decrease of the mitochondrial enzyme activity and increase of the activity of lysosomal and hydrolytic enzymes were found. These alterations reflect degenerative processes in cardiomyocytes followed by activation of their degradation and utilization. This results in the decrease of the myocardium contractile volume and its contractile function damage. There was no correlation between the level of the enzyme activity in the myocardium and the degree of the contractile function activity. There was a tendency to the increase of the above changes in patients with early signs of coronary atherosclerosis.     

Role of proliferation and differentiation of hemopoietic precursors in regeneration of hemopoiesis in cytostatic myelodepressions

Quantitative and qualitative composition of hemopoietic tissue and the intensity of proliferation and differentiation of committed hemopoietic precursors are studied in mice treated with adriamycin, cyclophosphane, or 5-fluorouracil. It is shown that intense maturation of colony-forming units results in rapid regeneration of hemopoiesis even under conditions of reduced proliferation of these cells, whereas inhibition of their differentiation suppresses restoration of bone marrow cellularity despite intense proliferation of hemopoietic precursors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 12, pp. 616–620, December, 1997     

Dynamics of Functioning of Thyroid Gland Transplant under Conditions of Stimulation with Autologous Adherent Bone Marrow Cells

The efficiency of thyroid tissue autotransplantation was studied in 150 male Wistar rats for 3 months. Comparative analysis of functional competence of the thyroid tissue transplanted into the great omentum showed restoration of the thyroid hormonal activity in animals receiving cell suspension of autologous adherent bone marrow cells. __________ Translated from Kletochnye Tekhnologii v Biologii i Meditsine, No. 4, pp. 200–202, November, 2005     

Current problems of the pathological anatomy of ischemic (coronary) heart disease

Original and reported data are reviewed with respect to the development, from childhood onwards, of coronary arterial atherosclerosis. The leading contribution of coronary arterial thrombosis to myocardial infarction is demonstrated, as is high incidence of excentric atherosclerotic patches in coronary arteries, which are prone to spasm in the presence of such patches; the course and complications of left ventricular and right atrial or right ventricular infarction are described. Data on "incomplete", stable and unstable myocardial infarction are presented.     

Changes in myocardial metabolism and ultrastructure of myocardial microvessels during pharmacological and cold cardioplegia under hypothermic conditions without perfusion

A combination of pharmacological and cold cardioplegia in with hypothermia without perfusion in open-heart surgery guarantee the reversible character of shifts in energy and free radical balance in the myocardium. However, this procedure can impair coronary micricirculation due to structural and functional changes in microvessel endothelium. Our results demonstrate that new cytoprotective approaches are extremely needed for cardiac protection during surgery.     

Imaging of neurosphere oxygenation with phosphorescent probes

Multicellular spheroids are useful models of mammalian tissue for studies of cell proliferation, differentiation, replacement therapies and drug action. Having a size of 100–500 μm they mimic in vivo micro-environment and characteristic gradients of O₂, pH and nutrients. We describe the use of cell-penetrating O₂ probes based on phosphorescent Pt-porphyrins to perform high-resolution 2D and 3D mapping of O₂ in spheroid structures by live cell fluorescence imaging technique. Optimised procedures for preparation of neurospheres from cortical neural cells isolated from embryonic rat brain, their staining with the phosphorescent O₂ probes NanO2 and MM2 and subsequent analysis of oxygenation on different live cell imaging platforms, including widefield and confocal phosphorescence lifetime imaging microscopy (PLIM), conventional confocal and two-photon ratiometric intensity based O₂ detection are presented. This is followed by a series of physiological experiments in which oxygenation patterns of the neurospheres are correlated with culturing conditions (atmospheric hypoxia and hyperoxia, size, growth factors), distribution of stem cells, mature neurons and astrocytes, HIF-2α stabilisation and responses to metabolic stimulation. The O₂ imaging method allows multiplexing with many conventional fluorescent probes to perform multi-parametric imaging analysis of cells in 3D microenvironment. It can be applied to other types of spheroids and 3D tissue models.     

Changing nutrient cycling in Lake Baikal,the world’s oldest lake

Lake Baikal, lying in a rift zone in southeastern Siberia, is the world''s oldest, deepest, and most voluminous lake that began to form over 30 million years ago. Cited as the “most outstanding example of a freshwater ecosystem” and designated a World Heritage Site in 1996 due to its high level of endemicity, the lake and its ecosystem have become increasingly threatened by both climate change and anthropogenic disturbance. Here, we present a record of nutrient cycling in the lake, derived from the silicon isotope composition of diatoms, which dominate aquatic primary productivity. Using historical records from the region, we assess the extent to which natural and anthropogenic factors have altered biogeochemical cycling in the lake over the last 2,000 y. We show that rates of nutrient supply from deep waters to the photic zone have dramatically increased since the mid-19th century in response to changing wind dynamics, reduced ice cover, and their associated impact on limnological processes in the lake. With stressors linked to untreated sewage and catchment development also now impacting the near-shore region of Lake Baikal, the resilience of the lake’s highly endemic ecosystem to ongoing and future disturbance is increasingly uncertain.

Ancient lakes have long been associated with both high levels of biodiversity and endemicity. However, they are also being threatened by anthropogenic forcings that have led to impacts ranging from the warming of lake waters (1), hydrological modifications (2), increases in aquatic toxicity (3), and declining endemic populations due to introductions of nonnative species (4). With global populations increasingly reliant on large and ancient lakes for ecosystem services, the biodiversity (5) and value of aquatic systems to society (6), particularly in ancient lake systems (7), are at risk. Lake Baikal (Russia) is an exceptional example of an ancient lake (Fig. 1). In addition to containing ∼20% of global surface freshwater, the lake is characterized by its high degree of biodiversity with over 2,500 flora and fauna, the majority of which are endemic (8). This has been attributed to the lake’s age and fully oxygenated water column, driven by seasonal overturning and deep water renewal (9, 10) that sustains an almost completely endemic deep water fauna (8).Open in a separate windowFig. 1.Location of Lake Baikal and its catchment (gray) together with the location of World Meteorological Organization station in Irkutsk, major catchment rivers (brown), coring sites (BAIK13-1, BAIK13-4), and sites providing additional data used in this study (BAIK13-7).Concerns exist over the future health of this unique ecosystem, amid evidence of extensive shoreline eutrophication (11, 12) and climate-induced shifts in primary productivity (13, 14). Together, these changes have impacted organisms ranging from sponges and gastropods to ciliates, flagellates, and algal communities (15). Given the likelihood of future anthropogenic disturbance on Lake Baikal, further disrupting productivity exchanges through the lake’s food web, there is a need to place these contemporary observations into their historical setting. In Lake Baikal, we have evidence that algal communities have undergone rapid multidecadal to multicentennial timescale changes over the last 2,000 y (16). However, there is a need to also gain a clearer insight into how biogeochemical and nutrient cycling has altered over the same timescale, both to contextualize natural and anthropogenic drivers of change and to understand the susceptibility of the lake’s ecosystem to further alteration under different climate states (17). Annual primary productivity in Lake Baikal is ultimately regulated by photic zone nutrient availability, in addition to ice/snow cover, which regulates light availability for photosynthesis (10, 18). Here, by analyzing the silicon isotope composition of diatom silica (δ³⁰Si_diatom), we show that nutrient supply to the surface waters of Lake Baikal has rapidly increased through the 20th and 21st centuries coincident with increased wind-driven Ekman transport and reduced ice cover. These changes in photic zone nutrient availability have the potential to alter resource competition and prey–predator interactions across the lake (15, 19).