Potential Species Dependency for the Pulmonary Antiallergic Effects of Aerosolized Heparin

1993 ◽  
Vol 6 (4) ◽  
pp. 237-239 ◽  
Author(s):  
R.E. Howell ◽  
S.L. Woeppel
Keyword(s):  
Species Dependency

Alkaline phosphatase activity in the western English Channel

1988 ◽  
Vol 68 (2) ◽  
pp. 239-250 ◽  
Author(s):  
Anthony G. Davies ◽  
M. Ann Smith
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Surface Waters ◽  
English Channel ◽  
Half Saturation Constant ◽  
Phosphate Inhibition ◽  
Vertical Distributions ◽  
Gyrodinium Aureolum ◽  
Species Dependency

The spatial and vertical distributions of alkaline phosphatase activity (APA) in the western English Channel in July 1987 were determined using 2 μM 3-O-methylfluorescein phosphate as substrate. The response of APA to increases in substrate concentration followed Michaelis-Menten kinetics but differences in Ks values between stations suggested a species dependency of the half-saturation constant. Phosphate inhibition of APA was, however, similar at 3 locations. The chlorophyll specific APA (SAPA) in surface waters ranged from 0.004 to 0.57 nMPO43- μg chla-1 min-1 and was inversely exponentially related to the chlorophyll a concentration reflecting the fact that phytoplankton populations are largest where inorganic nutrient availability is greatest and synthesis of the enzyme is not derepressed. SAPA values were found to be low in the bloom of Gyrodinium aureolum in the Ushant front and in the sub-surface chlorophyll maximum in the stratified region. Vertical distributions of SAPA are discussed in terms of the hydrographic characteristics of the water column and an attempt has been made to distinguish between APA associated with phytoplankton and with bacteria.

scholarly journals Mitochondria in the Nuclei of Rat Myocardial Cells

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 712 ◽  
Author(s):  
Chupalav M. Eldarov ◽  
Irina M. Vangely ◽  
Valeriya B. Vays ◽  
Eugene V. Sheval ◽  
Susanne Holtze ◽  
...  
Keyword(s):  
Direct Interaction ◽  
Mitochondrial Network ◽  
Myocardial Cells ◽  
Biological Phenomenon ◽  
Electron Microscopic ◽  
Heterocephalus Glaber ◽  
Interfibrillar Mitochondria ◽  
Normal Rat ◽  
Rat Cardiac Myocytes ◽  
Species Dependency

Electron microscopic study of cardiomyocytes taken from healthy Wistar and OXYS rats and naked mole rats (Heterocephalus glaber) revealed mitochondria in nuclei that lacked part of the nuclear envelope. The direct interaction of mitochondria with nucleoplasm is shown. The statistical analysis of the occurrence of mitochondria in cardiomyocyte nuclei showed that the percentage of nuclei with mitochondria was roughly around 1%, and did not show age and species dependency. Confocal microscopy of normal rat cardiac myocytes revealed a branched mitochondrial network in the vicinity of nuclei with an organization different than that of interfibrillar mitochondria. This mitochondrial network was energetically functional because it carried the membrane potential that responded by oscillatory mode after photodynamic challenge. We suggest that the presence of functional mitochondria in the nucleus is not only a consequence of certain pathologies but rather represents a normal biological phenomenon involved in mitochondrial/nuclear interactions.

Species Dependency of the Compositional Indirect Noise Mechanism

2017 ◽  
Author(s):  
Jeffrey D. O’Brien ◽  
Matthias Ihme
Keyword(s):  
Combustion Products ◽  
Operating Conditions ◽  
Hydrocarbon Fuels ◽  
Excess Noise ◽  
Individual Species ◽  
Underlying Structure ◽  
Mean Flow ◽  
Specific Level ◽  
Product Gas ◽  
Species Dependency

Indirect combustion noise is a growing concern for aviation engine designers. It is typically associated with the distortion of “hot spots” (entropy structures) and vortical structures that generate excess noise as they are convected by an accelerating mean flow. Recently, it has been shown theoretically that fluctuations in a gas’s chemical composition can act as an additional source of indirect noise in aviation engines. This work examines this composition noise mechanism, focusing on the underlying chemical effects that drive this source of indirect noise. Since the mechanism has yet to be confirmed experimentally, this paper begins by applying the theory to inert mixtures of noble gases and air, in an attempt to guide experimentalists by identifying the set of operating conditions that will produce the strongest acoustic response. Turning from non-reacting to reacting flows, the paper next examines the sensitivity of the compositional noise mechanism to fuel type, testing several common fuels. It is found that, while there is a substantial difference between hydrogen and hydrocarbon fuels, overall noise levels vary only slightly between different hydrocarbon fuels. Additionally, there appears to be a common underlying structure to the response of a product-gas mixture generated by burning a fuel, which is explained through linearized theory and confirmed with numerical results. Lastly, the physics of composition noise is examined at the species-specific level, attempting to provide a link between individual combustion products and changes in a mixture’s propensity to generate indirect noise. The sensitivity of individual species can be explained by a combination of differences between the species and mixture’s Gibbs free energy and strong gradients in product gas concentration with mixture fraction. However, by analyzing the species dependency of combustion products at several different mean mixture fractions, it is found that no single species dominates the noise generation over the combustor’s entire range, but rather the most acoustically active species varies strongly with local stoichiometry.

Purine efflux after cardiac ischemia: relevance to allopurinol cardioprotection

1987 ◽  
Vol 252 (2) ◽  
pp. H368-H373 ◽  
Author(s):  
C. M. Grum ◽  
L. H. Ketai ◽  
C. L. Myers ◽  
M. Shlafer
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Left Ventricular ◽  
Oxygen Radical ◽  
Total Absence ◽  
Rabbit Myocardium ◽  
Heart Preparation ◽  
Radical Generation ◽  
Key Indicators ◽  
Species Dependency

Allopurinol is thought to protect hearts against damage due to hypoxia or ischemia by inhibiting xanthine oxidase and oxygen radical generation. We subjected isolated rabbit hearts, equilibrated by perfusion at 37 degrees C, to 1 h of global ischemia at 27 or 37 degrees C with or without brief pretreatment with 100 microM allopurinol. The total absence of xanthine or uric acid in the coronary effluent following ischemia, the presence of hypoxanthine (25 +/- 4 microM peak concentration), and the failure of allopurinol to alter purine washout profiles or postischemic cardiac function suggest that rabbit myocardium lacks xanthine oxidase or dehydrogenase. Data obtained with a similar rat heart preparation showed appreciable formation of xanthine (12 +/- 2 microM peak) and uric acid (10 +/- 3 microM). Allopurinol pretreatment inhibited xanthine and uric acid formation and significantly improved key indicators of postischemic left ventricular function. We conclude that there is species dependency in the myocardial activity of xanthine oxidase or dehydrogenase, that when present it can be inhibited by acute allopurinol pretreatment, and that xanthine oxidase activity and its ability to generate oxygen radicals are not universal contributors to cardiac ischemic damage.

The phosphorylation state of casein and the species-dependency of its hypercholesterolaemic effect

1988 ◽  
Vol 59 (3) ◽  
pp. 467-473 ◽  
Author(s):  
Roelof Van Der Meer ◽  
Hielket De Vries ◽  
Gerrit Van Tintelen
Keyword(s):  
Phosphorylation State ◽  
Species Dependency
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