Glucocorticoid-mediated degradation of DNA in thymocytes of rats with transplantable Zajdela ascites hepatoma

Tumour growth was shown to be associated with DNA breakdown in thymocytes of rats bearing Zajdela ascites hepatomas. The tumour action on the thymus is mediated through adrenal glands since bilateral adrenalectomy completely prevents DNA breakdown in thymocytes. Using Southern hybridization of DNA genome with probes for histone, ribosomal and heat shock gene (hsp 70), it was shown that the degradation products of specific DNA sequences are as heterogenous as those of total DNA, although marked differences in appearance of nucleosomal ladder were seen. These data were interpreted to indicate different patterns of DNA breakdown in dying thymocytes. DNA breakdown in thymocytes in vivo and in isolated rat liver nuclei in vitro seems to proceed by similar mechanisms.     

Summer bacterio- and zooplankton in coastal waters of Svalbard

The distribution of bacterio- and zooplankton was studied in West Spitsbergen (Svalbard) coastal waters in August 2009. The bacterial abundance and biomass varied from 110 to 3360 × 10³ cells/ml and from 0.66 to 44.93 mg C/m³, respectively. These values were the highest in the surface water layers and decreased with depth. The greatest abundance of bacteria (5099 individuals/m3) was found in the freshened and warm water layer in Isfjorden. The highest biomass of zooplankton (182.41 mg C/m³) was registered in the zone of interaction of coastal and transformed Atlantic waters in the archipelago inner shelf. The spatial variations of abundance and biomass of the planktonic communities were related to the thermohaline characteristics of the water masses and, probably, to microalgal blooms.     

Various neurochemical aspects of the action of the tetrapeptide tuftsin on limbic system structures (histochemical and biochemical study)

Tetrapeptide tuftsin action on the activity of succinate dehydrogenase (SDG), malate dehydrogenase (MDG) and monoamine-oxidase (MAO) in microstructures of the neocortex, hippocampus and hypothalamus (supraoptic and paraventricular nuclei, retrochiasmic zone) has been investigated by means of histochemical methods. Simultaneously, pyruvate-, malate-, glutamate-, alfaketoglutamate-, succinate- and lactate-dehydrogenase activity in the neocortex and in the structures of the limbic system has been studied biochemically. SDG and MDG activity increases in neurons and glycocytes of all the hypothalamic formations mentioned. Changes in the activity of dehydrogenases in the hippocampus and neocortex under the same stimulation are less pronounced. MAO activity also increases in the nerve terminals converging on the bodies and dendrites of hypothalamic neurons and in the preterminal fibers of the neocortex, Tuftsin increases oxidative-reducing processes in various structures of the brain, but at the same time it possesses a predominant influence on the limbic system structures.     

The Change in the Linear Energy Transfer of a Clinical Proton Beam in the Presence of Gold Nanoparticles

Biophysics - Gold nanoparticles are promising radiosensitizers for proton radiotherapy. However, the physical mechanisms of gold nanoparticles radiosensitization remain unclear. In the present...     

Directed synthesis of 2',5'-oligoadenylates with increased stability towards phosphodiesterases

Phosphodiesterase stability of synthetic analogs of 2',5'-oligoadenylates, the mediators of antiviral and antiproliferative action of interferons was analysed. The analogs with a 3'-terminal acyclic nucleoside residue were prepared. These analogs were treated with NIH3T3 cell lysate, mice liver homogenate and snake venom phosphodiesterase. All analogs have demonstrated a high stability as compared with the natural 2',5'-oligoadenylate and its 3'-deoxyderivative. The possible biological activity of these stable analogs of 2',5'-oligoadenylates is discussed.     

Pixel classification method in optical coherence tomography for tumor segmentation and its complementary usage with OCT microangiography

A novel machine‐learning method to distinguish between tumor and normal tissue in optical coherence tomography (OCT) has been developed. Pre‐clinical murine ear model implanted with mouse colon carcinoma CT‐26 was used. Structural‐image‐based feature sets were defined for each pixel and machine learning classifiers were trained using “ground truth” OCT images manually segmented by comparison with histology. The accuracy of the OCT tumor segmentation method was then quantified by comparing with fluorescence imaging of tumors expressing genetically encoded fluorescent protein KillerRed that clearly delineates tumor borders. Because the resultant 3D tumor/normal structural maps are inherently co‐registered with OCT derived maps of tissue microvasculature, the latter can be color coded as belonging to either tumor or normal tissue. Applications to radiomics‐based multimodal OCT analysis are envisioned.      

Transcutaneous electrical stimulation of the spinal cord: A noninvasive tool for the activation of stepping pattern generators in humans

A new method for the activation of spinal locomotor networks (SLN) in humans by transcutaneous electrical spinal cord stimulation (tESCS) has been described. The tESCS applied in the region of the T11-T12 vertebrae with a frequency of 5?C40 Hz elicited involuntary step-like movements in healthy subjects with their legs suspended in a gravity-neutral position. The amplitude of evoked step-like movements increased with increasing tESCS frequency. The frequency of evoked step-like movements did not depend on the frequency of tESCS. It was shown that the hip, knee, and ankle joints were involved in the evoked movements. It has been suggested that tESCS activates the SPG (SLN) through in part, via the dorsal roots that enter the spinal cord. tESCS can be used as a noninvasive method in rehabilitation of spinal pathology.     

Development of Calbindin- and Calretinin-Immunopositive Neurons in the Enteric Ganglia of Rats

Calbindin D28 K (CB) and calretinin (CR) are the members of the EF-hand family of calcium-binding proteins that are expressed in neurons and nerve fibers of the enteric nervous system. CB and CR are expressed differentially in neuronal subpopulations throughout the central and peripheral nervous systems and their expression has been used to selectively target specific cell types and isolate neuronal networks. The present study presents an immunohistochemical analysis of CB and CR in the enteric ganglia of small intestine in rats of different ages (newborn, 10-day-old, 20-day-old, 30-day-old, 60-day-old, 1-year-old, and 2-year-old). The data obtained suggest a number of age-dependent changes in CB and CR expression in the myenteric and submucous plexuses. In the myenteric plexus, the lowest percentage of CB-immunoreactive (IR) and CR-IR neurons was observed at birth, after which the number of IR cells increased in the first 10 days of life. In the submucous plexus, CB-IR and CR-IR neurons were observed from 10-day-old onwards. The percentage of CR-IR and CB-IR neurons increased in the first 2 months and in the first 20 days, respectively. In all animals, the majority of the IR neurons colocalized CR and CB. From the moment of birth, the mean of the cross-sectional area of the CB-IR and CR-IR neuronal profiles was larger than that of CB- and CR-negative cells.     

The Motor Synergies’ Organization Features at Different Levels of Motor Control during High Coordinated Human’s Movement

Journal of Evolutionary Biochemistry and Physiology - The study considers the synergetic effects manifested at the level of interaction between the various parts of the musculoskeletal system with...