331 research outputs found

    Maturity, ovarian cycle, fecundity, and age-specific parturition of black rockfish (Sebastes melanops)

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    From 1995 to 1998, we collected female black rockfish (Sebastes melanops) off Oregon in order to describe their basic reproductive life history and determine age-specific fecundity and temporal patterns in parturition. Female black rockfish had a 50% probability of being mature at 394 mm fork length and 7.5 years-of-age. The proportion of mature fish age 10 or older significantly decreased each year of this study, from 0.511 in 1996 to 0.145 in 1998. Parturition occurred between mid-January and mid-March, and peaked in February. We observed a trend of older females extruding larvae earlier in the spawning season and of younger fish primarily responsible for larval production during the later part of the season. There were differences in absolute fecundity at age between female black rockfish with prefertilization oocytes and female black rockfish with fertilized eggs; fertilized-egg fecundity estimates were considered superior. The likelihood of yolked oocytes reaching the developing embryo stage increased with maternal age. Absolute fecundity estimates (based on fertilized eggs) ranged from 299,302 embryos for a 6-year-old female to 948,152 embryos for a 16-year-old female. Relative fecundity (based on fertilized eggs) increased with age from 374 eggs/g for fish age 6 to 549 eggs/g for fish age 16

    Nitro-Triarylmethyl Radical as Dual Oxygen and Superoxide Probe

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    Superoxide radical is involved in numerous physiological and pathophysiological processes. Tetrathiatriarylmethyl (TAM) radicals are knows to react with superoxide allowing measurement of superoxide production in biological media. We report the synthesis of a Nitro conjugated TAM radical showing a rate constant of 7 Γ— 105 Mβˆ’1sβˆ’1 which is two order of magnitude higher than other TAMs allowing high sensitivity measurement of superoxid

    Concurrent Longitudinal EPR Monitoring of Tissue Oxygenation, Acidosis, and Reducing Capacity in Mouse Xenograft Tumor Models

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    Tissue oxygenation, extracellular acidity and tissue reducing capacity are among crucial parameters of tumor microenvironment (TME) of significant importance for tumor pathophysiology. In this paper we demonstrate the complementary application of particulate lithium octa-n-butoxy-naphthalocyanine (LiNc-BuO) and soluble nitroxide (NR) paramagnetic probes for monitoring of these TME parameters using electron paramagnetic resonance (EPR) technique. Two different types of therapeutic interventions were studied: hypothermia and systemic administration of metabolically active drug. In summary, the results demonstrate utility of EPR technique for noninvasive concurrent longitudinal monitoring of physiologically relevant chemical parameters of TME in a mouse xenograft tumor models including that under therapeutic intervention

    ΠΠ°Ρ€ΡƒΡˆΠ΅Π½ΠΈΠ΅ ΠΊΠΎΠΎΡ€Π΄ΠΈΠ½Π°Ρ†ΠΈΠΈ Π΄Π²ΠΈΠΆΠ΅Π½ΠΈΠΉ Hoilungia hongkongensis (Placozoa) Π² присутствии ΠΈΠΎΠ½ΠΎΠ² Zn2+

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    Hoilungia hongkongensis ΠΏΡ€ΠΈΠ½Π°Π΄Π»Π΅ΠΆΠΈΡ‚ ΠΊ Ρ‚ΠΈΠΏΡƒ пластинчатыС (Placozoa) β€” ΠΏΡ€ΠΎΡΡ‚Π΅ΠΉΡˆΠΈΠΌ ΠΌΠ½ΠΎΠ³ΠΎΠΊΠ»Π΅Ρ‚ΠΎΡ‡Π½Ρ‹ΠΌ ΠΎΡ€Π³Π°Π½ΠΈΠ·ΠΌΠ°ΠΌ с динамичСским ΠΏΠ»Π°Π½ΠΎΠΌ строСния Ρ‚Π΅Π»Π°. Π’ ΠΏΠΎΠ΄Π΄Π΅Ρ€ΠΆΠ°Π½ΠΈΠΈ цСлостности этих ΠΆΠΈΠ²ΠΎΡ‚Π½Ρ‹Ρ… Π²Π°ΠΆΠ½ΡƒΡŽ Ρ€ΠΎΠ»ΡŒ ΠΈΠ³Ρ€Π°ΡŽΡ‚ ΠΈΠΎΠ½Ρ‹ ΠΊΠ°Π»ΡŒΡ†ΠΈΡ. Π’ настоящСй Ρ€Π°Π±ΠΎΡ‚Π΅ ΡΠΊΡΠΏΠ΅Ρ€ΠΈΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½ΠΎ ΠΈΠ·ΡƒΡ‡Π΅Π½ΠΎ влияниС ΠΈΠΎΠ½ΠΎΠ² Ρ†ΠΈΠ½ΠΊΠ° Π½Π° взаимодСйствиС ΠΊΠ»Π΅Ρ‚ΠΎΠΊ H. hongkongensis. ΠŸΡ€ΠΈ ΡƒΠ²Π΅Π»ΠΈΡ‡Π΅Π½ΠΈΠΈ ΠΊΠΎΠ½Ρ†Π΅Π½Ρ‚Ρ€Π°Ρ†ΠΈΠΈ ΠΈΠΎΠ½ΠΎΠ² Zn2+ Π½Π° 20–25 мкМ Π½Π°Ρ€ΡƒΡˆΠ°Π΅Ρ‚ΡΡ ΡΠΎΠ³Π»Π°ΡΠΎΠ²Π°Π½Π½ΠΎΡΡ‚ΡŒ Π°ΠΌΡ‘Π±ΠΎΠΈΠ΄Π½ΠΎΠ³ΠΎ двиТСния, Ρ‡Ρ‚ΠΎ ΠΏΡ€ΠΈΠ²ΠΎΠ΄ΠΈΡ‚ ΠΊ ΠΎΠ±Ρ€Π°Π·ΠΎΠ²Π°Π½ΠΈΡŽ «вСтвистых» Ρ„ΠΎΡ€ΠΌ ΠΆΠΈΠ²ΠΎΡ‚Π½ΠΎΠ³ΠΎ. Π›ΠΎΠΊΠΎΠΌΠΎΡ‚ΠΎΡ€Π½Ρ‹Π΅ рСснитчатыС ΠΊΠ»Π΅Ρ‚ΠΊΠΈ Π΄Π²ΠΈΠ³Π°ΡŽΡ‚ΡΡ Ρ…Π°ΠΎΡ‚ΠΈΡ‡Π½ΠΎ ΠΈ нСзависимо Π΄Ρ€ΡƒΠ³ ΠΎΡ‚ Π΄Ρ€ΡƒΠ³Π°. ЭкспСримСнты ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ, Ρ‡Ρ‚ΠΎ ΠΊΠΎΠ½Ρ‚Π°ΠΊΡ‚Π½ΠΎΠ΅ взаимодСйствиС ΠΊΠ»Π΅Ρ‚ΠΎΠΊ H. hongkongensis Π²Π°ΠΆΠ½ΠΎ для скоординированных Π΄Π²ΠΈΠΆΠ΅Π½ΠΈΠΉ ΠΎΡ€Π³Π°Π½ΠΈΠ·ΠΌΠ°, Π² Ρ‚ΠΎ врСмя ΠΊΠ°ΠΊ ΠΈΠΎΠ½Ρ‹ Ρ†ΠΈΠ½ΠΊΠ° ΠΌΠΎΠ³ΡƒΡ‚ ΠΊΠΎΠ½ΠΊΡƒΡ€ΠΈΡ€ΠΎΠ²Π°Ρ‚ΡŒ с ΠΈΠΎΠ½Π°ΠΌΠΈ ΠΊΠ°Π»ΡŒΡ†ΠΈΡ, Π½Π°Ρ€ΡƒΡˆΠ°Ρ Ρ€Π΅Π³ΡƒΠ»ΡΡ†ΠΈΡŽ ΠΈ Ρ€Π°Π·Ρ€ΡƒΡˆΠ°Ρ связь ΠΌΠ΅ΠΆΠ΄Ρƒ ΠΊΠ»Π΅Ρ‚ΠΊΠ°ΠΌΠΈ

    Tuning the size and composition of manganese oxide nanoparticles through varying temperature ramp and aging time

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    Manganese oxide (MnO) nanoparticles (NPs) can serve as robust pH-sensitive contrast agents for magnetic resonance imaging (MRI) due to Mn2+ release at low pH, which generates a ~30 fold change in T1 relaxivity. Strategies to control NP size, composition, and Mn2+ dissolution rates are essential to improve diagnostic performance of pH-responsive MnO NPs. We are the first to demonstrate that MnO NP size and composition can be tuned by the temperature ramping rate and aging time used during thermal decomposition of manganese(II) acetylacetonate. Two different temperature ramping rates (10Β°C/min and 20Β°C/min) were applied to reach 300Β°C and NPs were aged at that temperature for 5, 15, or 30 min. A faster ramping rate and shorter aging time produced the smallest NPs of ~23 nm. Shorter aging times created a mixture of MnO and Mn3O4 NPs, whereas longer aging times formed MnO. Our results indicate that a 20Β°C/min ramp rate with an aging time of 30 min was the ideal temperature condition to form the smallest pure MnO NPs of ~32 nm. However, Mn2+ dissolution rates at low pH were unaffected by synthesis conditions. Although Mn2+ production was high at pH 5 mimicking endosomes inside cells, minimal Mn2+ was released at pH 6.5 and 7.4, which mimic the tumor extracellular space and blood, respectively. To further elucidate the effects of NP composition and size on Mn2+ release and MRI contrast, the ideal MnO NP formulation (~32 nm) was compared with smaller MnO and Mn3O4 NPs. Small MnO NPs produced the highest amount of Mn2+ at acidic pH with maximum T1 MRI signal; Mn3O4 NPs generated the lowest MRI signal. MnO NPs encapsulated within poly(lactide-co-glycolide) (PLGA) retained significantly higher Mn2+ release and MRI signal compared to PLGA Mn3O4 NPs. Therefore, MnO instead of Mn3O4 should be targeted intracellularly to maximize MRI contrast

    Development of Multifunctional Overhauser-enhanced Magnetic Rresonance Imaging for Concurrent in Vivo Mapping of Tumor Interstitial Oxygenation, Acidosis and Inorganic Phosphate Concentration

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    Tumor oxygenation (pO2), acidosis (pH) and interstitial inorganic phosphate concentration (Pi) are important parameters of the malignant behavior of cancer. A noninvasive procedure that enables visualization of these parameters may provide unique information about mechanisms of tumor pathophysiology and provide clues to new treatment targets. In this research, we present a multiparametric imaging method allowing for concurrent mapping of pH, spin probe concentration, pO2, and Pi using a single contrast agent and Overhauser-enhanced magnetic resonance imaging technique. The developed approach was applied to concurrent multifunctional imaging in phantom samples and in vivo in a mouse model of breast cancer. Tumor tissues showed higher heterogeneity of the distributions of the parameters compared with normal mammary gland and demonstrated the areas of significant acidosis, hypoxia, and elevated Pi content

    Evaluation of the efficiency of biocomposting of bottom silt deposits using different conditions of aerobic fermentation

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    The efficiency of biocomposting of bottom silt deposits was evaluated in laboratory conditions. The biocomposting process is reproduced taking into account the main technological parameters and using lowland peat, microbial concentrate and vermiculture as basic components. The composition of the microbial concentrate includes strains of the genera Bacillus spp., Clostridium spp., Pseudomonas spp., causing biosolubilization of a complex organomineral substrate - bottom sediments. The productive line Eisenia foetida Savigny (Lumbricidae) was used as a vermiculture. The evaluation of the efficiency of biocomposting was carried out according to agrochemical characteristics. The greatest effect on the preservation of biogens was obtained during the fermentation of bottom sediments with the participation of microbial concentrate. An increase in the content of N to 1.10%, P – to 0.54%, K – to 0.42% was achieved. The use of vermiculture caused an increase in organic matter – up to 42.1% and humus – up to 14.6%. The results of the experiment allow us to consider biocompost and vermicompost obtained using bottom sediments as a source of elements necessary for plant growth and development

    Interstitial Inorganic Phosphate as a Tumor Microenvironment Marker for Tumor Progression

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    Noninvasive in vivo assessment of chemical tumor microenvironment (TME) parameters such as oxygen (pO2), extracellular acidosis (pHe), and concentration of interstitial inorganic phosphate (Pi) may provide unique insights into biological processes in solid tumors. In this work, we employ a recently developed multifunctional trityl paramagnetic probe and electron paramagnetic resonance (EPR) technique for in vivo concurrent assessment of these TME parameters in various mouse models of cancer. While the data support the existence of hypoxic and acidic regions in TME, the most dramatic differences, about 2-fold higher concentrations in tumors vs. normal tissues, were observed for interstitial Pi - the only parameter that also allowed for discrimination between non-metastatic and highly metastatic tumors. Correlation analysis between [Pi], pO2, pHe and tumor volumes reveal an association of high [Pi] with changes in tumor metabolism and supports different mechanisms of protons and Pi accumulation in TME. Our data identifies interstitial inorganic phosphate as a new TME marker for tumor progression. Pi association with tumor metabolism, buffer-mediated proton transport, and a requirement of high phosphorus content for the rapid growth in the β€œgrowth rate hypothesis” may underline its potential role in tumorigenesis and tumor progression

    Interstitial Inorganic Phosphate as a Tumor Microenvironment Marker for Tumor Progression

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    Noninvasive in vivo assessment of chemical tumor microenvironment (TME) parameters such as oxygen (pO2), extracellular acidosis (pHe), and concentration of interstitial inorganic phosphate (Pi) may provide unique insights into biological processes in solid tumors. In this work, we employ a recently developed multifunctional trityl paramagnetic probe and electron paramagnetic resonance (EPR) technique for in vivoconcurrent assessment of these TME parameters in various mouse models of cancer. While the data support the existence of hypoxic and acidic regions in TME, the most dramatic differences, about 2-fold higher concentrations in tumors vs. normal tissues, were observed for interstitial Pi - the only parameter that also allowed for discrimination between non-metastatic and highly metastatic tumors. Correlation analysis between [Pi], pO2, pHe and tumor volumes reveal an association of high [Pi] with changes in tumor metabolism and supports different mechanisms of protons and Pi accumulation in TME. Our data identifies interstitial inorganic phosphate as a new TME marker for tumor progression. Pi association with tumor metabolism, buffer-mediated proton transport, and a requirement of high phosphorus content for the rapid growth in the β€œgrowth rate hypothesis” may underline its potential role in tumorigenesis and tumor progression
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