Смешанный клеточный метод умножения матриц

Запропоновано змішаний клітинний метод множення матриць, який сполучає метод Штрассена зі швидким клітинним методом множення матриць, взаємодія яких мінімізує на 25 % мультиплікативну та адитивну складності відомих алгоритмів матричного множення. Наведено оцінки обчислювальної складності клітинних аналогів зазначених алгоритмів, отриманих на основі змішаного методу.A mixed cellular method of matrix multiplication is proposed that combines the Strassen method with a fast cellular method of matrix multiplication. The interaction of these methods makes it possible to decrease the multiplicative and additive complexities of well-known matrix multiplication algorithms by 25%. Estimates of computational complexity of cellular analogues of the mentioned algorithms are given

Carbohydrate supplementation during prolonged cycling exercise spares muscle glycogen but does not affect intramyocellular lipid use

Using contemporary stable-isotope methodology and fluorescence microscopy, we assessed the impact of carbohydrate supplementation on whole-body and fiber-type-specific intramyocellular triacylglycerol (IMTG) and glycogen use during prolonged endurance exercise. Ten endurance-trained male subjects were studied twice during 3 h of cycling at 63 ± 4% of maximal O2 uptake with either glucose ingestion (CHO trial; 0.7 g CHO kg−1 h−1) or without (CON placebo trial; water only). Continuous infusions with [U-13C] palmitate and [6,6-2H2] glucose were applied to quantify plasma free fatty acids (FFA) and glucose oxidation rates and to estimate intramyocellular lipid and glycogen use. Before and after exercise, muscle biopsy samples were taken to quantify fiber-type-specific IMTG and glycogen content. Plasma glucose rate of appearance (Ra) and carbohydrate oxidation rates were substantially greater in the CHO vs CON trial. Carbohydrate supplementation resulted in a lower muscle glycogen use during the first hour of exercise in the CHO vs CON trial, resulting in a 38 ± 19 and 57 ± 22% decreased utilization in type I and II muscle-fiber glycogen content, respectively. In the CHO trial, both plasma FFA Ra and subsequent plasma FFA concentrations were lower, resulting in a 34 ± 12% reduction in plasma FFA oxidation rates during exercise (P < 0.05). Carbohydrate intake did not augment IMTG utilization, as fluorescence microscopy revealed a 76 ± 21 and 78 ± 22% reduction in type I muscle-fiber lipid content in the CHO and CON trial, respectively. We conclude that carbohydrate supplementation during prolonged cycling exercise does not modulate IMTG use but spares muscle glycogen use during the initial stages of exercise in endurance-trained men

UČINAK TRANSPORTA I ZAKAŠNJELE ANALIZE HEMATOLOŠKIH VARIJABLA U UZORCIMA KRVI UZETIH OD VRHUNSKIH BRZIH KLIZAČA

To study the effect of transport and storage on the stability of hematological variables, two blood samples from 81 elite short track speed skaters were analyzed within four hours after sampling. One sample was analyzed again 24 hours later. After analysis, the second sample was subjected to road and air transport and analyzed a third time 24 hours after the second analysis. To study the effect of storage up to 48 hours, one blood sample was taken from each of 81 elite long track speed skaters and subsequently analyzed within four hours after sampling, and again after 24 and 48 hours. Transporting the blood samples and storing them for 24 hours did not significantly change hemoglobin concentration and % reticulocytes. Hematocrit and the difference between total measured hemoglobin and cellular hemoglobin concentration were increased after 24 hours (p<0.01). In samples stored for 48 hours, hemoglobin concentration remained stable for up to the entire 48-hour time period. In contrast, after 24 hours the mean cellular volume (MCV) increased (p<0.05). After 48 hours hematocrit (p<0.05), percentage and number of reticulocytes increased 48 hours after sampling (p<0.01). In conclusion, hemoglobin concentration and percentage of reticulocytes may remain stable for up to 24 hours after sampling, while hematocrit may increase during this time period. Furthermore, hematocrit, MCV, and percentage and number of reticulocytes may also rise during the 24 hours after sampling. However, when transport is involved hemolysis may occur.Cilj rada bio je ispitati utjecaj transporta i skladištenja uzoraka krvi na stabilnost hematoloških varijabli. Dva uzorka krvi uzeta od 81 vrhunska brza klizača na kratke staze analizirana su unutar 4 sata nakon uzimanja. Jedan je uzorak ponovno analiziran nakon 24 sata. Po prvoj analizi, drugi je uzorak transportiran, cestovnim i zračnim prometom te ponovno analiziran nakon 24 sata. Kako bi se odredio utjecaj skladištenja uzoraka tijekom 48 sati, u 31 vrhunska brza klizača na duge staze, jedan je uzorak krvi analiziran unutar 4 sata nakon uzimanja te ponovno nakon 24 i 48 sati. Transport i skladištenje uzoraka krvi tijekom 24 sata nisu značajno promijenili koncentraciju hemoglobina i % retikulocita. Hematokrit te razlika između ukupnog hemoglobina i koncentracije staničnog hemoglobina povećala se nakon 24 sata (p<0.01). U uzorcima koji su bili uskladišteni tijekom 48 sata, koncentracija hemoglobina ostala je stabilna tijekom cjelokupnog vremenskog perioda. 24 sata nakon skladištenja došlo je do porasta srednjeg volumena eritrocita (MCV-a) (p<0.05), a 48 sati nakon skladištenja došlo je i do porasta hematokrita (p<0.05) te postotka i broja retikulocita (p<0.01). Koncentracija hemoglobina i postotak retikulocita ostaju stabilni i od 24 sata nakon uzimanja uzoraka krvi, dok hematokrit može porasti. Nakon 24 sata od uzimanja uzorka krvi raste hematokrit, MCV, postotak i broj retikulocita. Kada je uključen i transport uzoraka, može doći do njihove hemolize

Intravital correlated microscopy reveals differential macrophage and microglial dynamics during resolution of neuroinflammation

Many brain diseases involve activation of resident and peripheral immune cells to clear damaged and dying neurons. Which immune cells respond in what way to cues related to brain disease, however, remains poorly understood. To elucidate these in vivo immunological events in response to brain cell death we used genetically targeted cell ablation in zebrafish. Using intravital microscopy and large-scale electron microscopy, we defined the kinetics and nature of immune responses immediately following injury. Initially, clearance of dead cells occurs by mononuclear phagocytes, including resident microglia and macrophages of peripheral origin, whereas amoeboid microglia are exclusively involved at a later stage. Granulocytes, on the other hand, do not migrate towards the injury. Remarkably, following clearance, phagocyte numbers decrease, partly by phagocyte cell death and subsequent engulfment of phagocyte corpses by microglia. Here, we identify differential temporal involvement of microglia and peripheral macrophages in clearance of dead cells in the brain, revealing the chronological sequence of events in neuroinflammatory resolution. Remarkably, recruited phagocytes undergo cell death and are engulfed by microglia. Because adult zebrafish treated at the larval stage lack signs of pathology, it is likely that this mode of resolving immune responses in brain contributes to full tissue recovery. Therefore, these findings suggest that control of such immune cell behavior could benefit recovery from neuronal damage.</p

Supplementary data for article: Snijder, P. M.; Baratashvili, M.; Grzeschik, N. A.; Leuvenink, H. G. D.; Kuijpers, L.; Huitema, S.; Schaap, O.; Giepmans, B. N. G.; Kuipers, J.; Miljkovic, J. L.; et al. Overexpression of Cystathionine γ-Lyase Suppresses Detrimental Effects of Spinocerebellar Ataxia Type 3. Molecular Medicine 2015, 21, 758–768. https://doi.org/10.2119/molmed.2015.00221

Supplementary material for: [https://doi.org/10.2119/molmed.2015.00221]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2255

Intravital correlated microscopy reveals differential macrophage and microglial dynamics during resolution of neuroinflammation

Many brain diseases involve activation of resident and peripheral immune cells to clear damaged and dying neurons. Which immune cells respond in what way to cues related to brain disease, however, remains poorly understood. To elucidate these in vivo immunological events in response to brain cell death we used genetically targeted cell ablation in zebrafish. Using intravital microscopy and large-scale electron microscopy, we defined the kinetics and nature of immune responses immediately following injury. Initially, clearance of dead cells occurs by mononuclear phagocytes, including resident microglia and macrophages of peripheral origin, whereas amoeboid microglia are exclusively involved at a later stage. Granulocytes, on the other hand, do not migrate towards the injury. Remarkably, following clearance, phagocyte numbers decrease, partly by phagocyte cell death and subsequent engulfment of phagocyte corpses by microglia. Here, we identify differential temporal involvement of microglia and peripheral macrophages in clearance of dead cells in the brain, revealing the chronological sequence of events in neuroinflammatory resolution. Remarkably, recruited phagocytes undergo cell death and are engulfed by microglia. Because adult zebrafish treated at the larval stage lack signs of pathology, it is likely that this mode of resolving immune responses in brain contributes to full tissue recovery. Therefore, these findings suggest that control of such immune cell behavior could benefit recovery from neuronal damage

Carbohydrate supplementation during prolonged cycling exercise spares muscle glycogen but does not affect intramyocellular lipid use

Using contemporary stable-isotope methodology and fluorescence microscopy, we assessed the impact of carbohydrate supplementation on whole-body and fiber-type-specific intramyocellular triacylglycerol (IMTG) and glycogen use during prolonged endurance exercise. Ten endurance-trained male subjects were studied twice during 3 h of cycling at 63 ± 4% of maximal O2 uptake with either glucose ingestion (CHO trial; 0.7 g CHO kg−1 h−1) or without (CON placebo trial; water only). Continuous infusions with [U-13C] palmitate and [6,6-2H2] glucose were applied to quantify plasma free fatty acids (FFA) and glucose oxidation rates and to estimate intramyocellular lipid and glycogen use. Before and after exercise, muscle biopsy samples were taken to quantify fiber-type-specific IMTG and glycogen content. Plasma glucose rate of appearance (Ra) and carbohydrate oxidation rates were substantially greater in the CHO vs CON trial. Carbohydrate supplementation resulted in a lower muscle glycogen use during the first hour of exercise in the CHO vs CON trial, resulting in a 38 ± 19 and 57 ± 22% decreased utilization in type I and II muscle-fiber glycogen content, respectively. In the CHO trial, both plasma FFA Ra and subsequent plasma FFA concentrations were lower, resulting in a 34 ± 12% reduction in plasma FFA oxidation rates during exercise (P < 0.05). Carbohydrate intake did not augment IMTG utilization, as fluorescence microscopy revealed a 76 ± 21 and 78 ± 22% reduction in type I muscle-fiber lipid content in the CHO and CON trial, respectively. We conclude that carbohydrate supplementation during prolonged cycling exercise does not modulate IMTG use but spares muscle glycogen use during the initial stages of exercise in endurance-trained men

Overexpression of Cystathionine gamma-Lyase Suppresses Detrimental Effects of Spinocerebellar Ataxia Type 3

Spinocerebellar ataxia type 3 (SCA3) is a polyglutamine (polyQ) disorder caused by a CAG repeat expansion in the ataxin-3 (ATXN3) gene resulting in toxic protein aggregation. Inflammation and oxidative stress are considered secondary factors contributing to the progression of this neurodegenerative disease. There is no cure that halts or reverses the progressive neurodegeneration of SCA3. Here we show that overexpression of cystathionine.-lyase, a central enzyme in cysteine metabolism, is protective in a Drosophila model for SCA3. SCA3 flies show eye degeneration, increased oxidative stress, insoluble protein aggregates, reduced levels of protein persulfidation and increased activation of the innate immune response. Overexpression of Drosophila cystathionine.-lyase restores protein persulfidation, decreases oxidative stress, dampens the immune response and improves SCA3-associated tissue degeneration. Levels of insoluble protein aggregates are not altered; therefore, the data implicate a modifying role of cystathionine.-lyase in ameliorating the downstream consequence of protein aggregation leading to protection against SCA3-induced tissue degeneration. The cystathionine.-lyase expression is decreased in affected brain tissue of SCA3 patients, suggesting that enhancers of cystathionine.-lyase expression or activity are attractive candidates for future therapies