scholarly journals The Biological Significance of Haemoglobin in Nematode Parasites I. The Characteristics of the Purified Pigments

1949 ◽  
Vol 2 (3) ◽  
pp. 287 ◽  
Author(s):  
WP Rogers
Keyword(s):  
Carbon Monoxide ◽  
Linear Relationship ◽  
Equilibrium Constant ◽  
Haemonchus Contortus ◽  
Biological Significance ◽  
High Affinity ◽  
Nematode Parasites ◽  
A Value ◽  
Ammonium Sulphate Fractionation ◽  
Very High

Haemoglobins from Nippostrongylus muris, Nematodirus�spp., and Haemonchus contortus were purified by ammonium sulphate fractionation and their properties examined. All the haemoglobins showed a very high affinity for oxygen; the tension of half saturation (P50) for Nematodirus haemoglobin of concentrations about 1 x 10-4 g.-atoms of iron per 1. at pH 7.4 was in the region of 0.04 mm. of mercury. The P50 for H. contortus haemoglobin was similar to that of Nematodirus .spp.; N. muris haemoglobin had a somewhat higher p:;o' The. parasite haemoglobins all showed an unusually low affinity for carbon monoxide, the equilibrium constant, K = [HbCO] X p02/[Hb02] X pCO, having a value of about 1. The "span," the distance between the a-bands of oxyhaemoglobin and carboxyhaemoglobin, varied from 60 to 65 A. for the three parasites. None of the haemoglobins obtained from the parasites showed properties supporting the view that there is a linear relationship between log K and the "span."

scholarly journals The interaction of cations with lipopolysaccharide from Escherichia coli C as shown by measurement of binding constants and aggregation reactions

1989 ◽  
Vol 263 (3) ◽  
pp. 695-702 ◽  
Author(s):  
A M Field ◽  
E Rowatt ◽  
R J P Williams
Keyword(s):  
Escherichia Coli ◽  
Sodium Salt ◽  
Binding Constants ◽  
Assay Method ◽  
Aggregation State ◽  
High Affinity ◽  
A Value ◽  
High Affinity Site ◽  
Low Ionic Strength ◽  
Very High

Lipopolysaccharide from Escherichia coli C interacts with polyvalent cations at low ionic strength at more than one site. The first site has high affinity with a KD value of 10(-8) M for Ca2+ and even stronger binding for [(NH3)5CoNH2Co(NH3)5]5+ and La3+. The high-affinity site for the latter cations is beyond the sensitivity of the assay method. The second, low-affinity, site for bivalent cations has a Km of 10(-3) M, whereas, for tervalent and quinquevalent metal cations and spermine and hexacyclen (1,4,7,10,13,16-hexa-azacyclo-octadecane), this constant has a value of 10(-5) M. Binding of cations to the high-affinity site does not alter the aggregation state of the lipopolysaccharide, but combination with the low-affinity site gives particles twice the size of those of the sodium salt. Very high Ca2+ concentrations (30 mM) give particles eight times the size of those of the sodium salt.

scholarly journals The Biological Significance of Haemoglobin in Nematode Parasites II. The Properties of the Haemoglobins as Studied in Living Pabasites

1949 ◽  
Vol 2 (4) ◽  
pp. 399 ◽  
Author(s):  
WP Rogers
Keyword(s):  
Oxygen Tension ◽  
Haemonchus Contortus ◽  
Biological Significance ◽  
Water Soluble ◽  
Nematode Parasites

In the parasites examined, the amounts of water-soluble haematin compounds, of which haemoglobin formed the large part, varied considerably; Nippo$rongylus murls contained about 6 mg. (as haematin) per g. dry wt. of tissue, Nematodirus spp. and Haemonchus contortus about 0.8 mg. per g. dry wt. Evidence is presented which indicates that the haemoglobin of Nippo$rongylus muris may be oxygenated in vivo, at least sometimes. The haemoglobin in the living parasites was easily oxygenated and deoxygenated; when the oxygen tension in the medium surrounding the parasites in vitro at 37�C. fell below about 13 mm. of mercury (Nippostrongylus muris) or 9 mm. of mercury (Haemonchus contortus and Nematodirus spp.) the oxyhaemoglobin became deoxygenated.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

scholarly journals Tityus serrulatus venom contains two classes of toxins. Tityus gamma toxin is a new tool with a very high affinity for studying the Na+ channel.

1982 ◽  
Vol 257 (21) ◽  
pp. 12553-12558
Author(s):  
J Barhanin ◽  
J R Giglio ◽  
P Léopold ◽  
A Schmid ◽  
S V Sampaio ◽  
...  
Keyword(s):  
Na Channel ◽  
High Affinity ◽  
Tityus Serrulatus ◽  
Tityus Serrulatus Venom ◽  
Very High

scholarly journals Bacterial Culture Filtrates Antinematode Activity of Abomasum Bacterial Culture Filtrates against Haemonchus contortus in Small Ruminants

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1843
Author(s):  
Asfa Nazish ◽  
Fozia ◽  
Baharullah Khattak ◽  
Taj Ali Khan ◽  
Ijaz Ahmad ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Bacterial Culture ◽  
Small Ruminants ◽  
Adult Mortality ◽  
Comamonas Testosteroni ◽  
Bacterial Isolates ◽  
Egg Hatch ◽  
Nematode Parasites ◽  
Culture Filtrates ◽  
Nematode Mortality

Haemonchosis is a parasitic disease of small ruminants that adversely affects livestock production. Haemonchus contortus is one of the most prevalent nematode parasites that infect the abomasum of small ruminants. This parasite reduces milk production, overall growth and sometimes causes the death of the infected animals. The evaluation of the biocontrol potential of some abomasum bacterial isolates against H. contortus is investigated in this study. Out of which, three isolates—Comamonas testosteroni, Comamonas jiangduensis, Pseudomonas weihenstephanesis—show significant effect against the nematode L3, adult, and egg hatch inhibition assays. Various concentrations of metabolites from these bacteria are prepared and applied in different treatments compared with control. In the case of adult mortality assay, 50% metabolites of C. testosteroni and P. weihenstephanesis show 46% adult mortality, whereas C. jiangduensis shows 40% mortality. It is observed that decreasing the concentration of bacterial metabolite, lowers nematode mortality. The minimum nematode mortality rate is recorded at the lowest filtrates concentration of all the bacterial isolates. The same trend is observed in egg hatch inhibition assay, where the higher concentration of bacterial culture filtrates shows 100% inhibition of H. contortus egg. It is concluded that the effect of bacterial culture filtrates against H. contortus is dose-dependent for their activity against nematode L3, adult, and inhibition of egg hatchment.

N-terminal fragment of the anti-angiogenic human endostatin binds copper(II) with very high affinity

2009 ◽  
Vol 103 (7) ◽  
pp. 940-947 ◽  
Author(s):  
András Kolozsi ◽  
Attila Jancsó ◽  
Nóra V. Nagy ◽  
Tamás Gajda
Keyword(s):  
High Affinity ◽  
Terminal Fragment ◽  
Very High

scholarly journals Analysis of the coefficient of variation in shear and tensile bond strength tests

2005 ◽  
Vol 13 (3) ◽  
pp. 243-246 ◽  
Author(s):  
Fábio Lourenço Romano ◽  
Gláucia Maria Bovi Ambrosano ◽  
Maria Beatriz Borges de Araújo Magnani ◽  
Darcy Flávio Nouer
Keyword(s):  
Coefficient Of Variation ◽  
Mean Value ◽  
Scientific Article ◽  
A Value ◽  
Statistical Analysis System ◽  
Strength Tests ◽  
Analysis System ◽  
Very High

The coefficient of variation is a dispersion measurement that does not depend on the unit scales, thus allowing the comparison of experimental results involving different variables. Its calculation is crucial for the adhesive experiments performed in laboratories because both precision and reliability can be verified. The aim of this study was to evaluate and to suggest a classification of the coefficient variation (CV) for in vitro experiments on shear and tensile strengths. The experiments were performed in laboratory by fifty international and national studies on adhesion materials. Statistical data allowing the estimation of the coefficient of variation was gathered from each scientific article since none of them had such a measurement previously calculated. Excel worksheet was used for organizing the data while the sample normality was tested by using Shapiro Wilk tests (alpha = 0.05) and the Statistical Analysis System software (SAS). A mean value of 6.11 (SD = 1.83) for the coefficient of variation was found by the data analysis and the data had a normal distribution (p>0.05). A range classification was proposed for the coefficient of variation from such data, that is, it should be considered low for a value lesser than 2.44; intermediate for a value between 2.44 and 7.94, high for a value between 7.94 and 9.78, and finally, very high for a value greater than 9.78. Such classification can be used as a guide for experiments on adhesion materials, thus making the planning easier as well as revealing precision and validity concerning the data.

Vibration-rotation bands and rotational constants of dideuteroacetylene

1955 ◽  
Vol 232 (1190) ◽  
pp. 291-309 ◽  
Keyword(s):  
Resolving Power ◽  
Vibrational States ◽  
Absorption Bands ◽  
Rotational Constants ◽  
Vibrational Assignments ◽  
Vibrational Anharmonicity ◽  
A Value ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Very High

Nine vibrational absorption bands of dideutero-acetylene have been examined with very high resolving power. The rotational constants have been determined for the vibrational levels concerned, and the coefficients α i have been determined with more convincing accuracy than previously. In some of the bands the Q branches have been resolved, so that the l -doubling coefficients q i could be derived, and details could be established about the doublet components in some II levels. The results emphasize the need of high resolution if the vibrational assignments are to be unambiguous, and if reliable values of the rotational constants are to be derived. A value of B e has been obtained, and the vibrational anharmonicity coefficients have been considered briefly. Estimates of the centrifugal stretching constants D i in different vibrational states have been made, and one anomalous case has been found.

The stability of onoratoite, Sb8O11Cl2, in the supergene environment

2014 ◽  
Vol 78 (7) ◽  
pp. 1671-1675 ◽  
Author(s):  
Adam J. Roper ◽  
Peter Leverett ◽  
Timothy D. Murphy ◽  
Peter A. Williams
Keyword(s):  
Significant Influence ◽  
Secondary Phase ◽  
Low Ph ◽  
Stable Phase ◽  
Supergene Zone ◽  
A Value ◽  
Solubility Studies ◽  
The Stability ◽  
Very High

AbstractSynthesis and solubility studies of onoratoite have been undertaken to determine the role of this rare secondary phase in the immobilization of Sb and the conditions responsible for its formation in the supergene zone. Solubility studies were undertaken at 298.15 K. A value of ΔGfθ (Sb8O11Cl2, s, 298.15 K) = –2576 ±12 kJ mol–1 was derived. Calculations involving sénarmontite, Sb2O3, klebelsbergite, Sb4O4SO4(OH)2 and schafarzikite, FeSb2O4, show that onoratoite is a thermodynamically stable phase only at negligible activities of SO42–(aq) and low activities of Fe2+(aq), at low pH and very high activities of Cl–(aq). This explains why onoratoite is such a rare secondary phase and why it cannot exert any significant influence on the dispersion of Sb in the supergene environment.

scholarly journals The effect of temperature on the oxygen dissociation curves of whole blood of larval and adult lampreys (Geotria australis)

1982 ◽  
Vol 97 (1) ◽  
pp. 253-261
Author(s):  
D. J. Macey ◽  
I. C. Potter
Keyword(s):  
Whole Blood ◽  
Life Cycle Stage ◽  
Effect Of Temperature ◽  
High Affinity ◽  
Oxygen Dissociation ◽  
Geotria Australis ◽  
Oxygen Tensions ◽  
Dissociation Curves ◽  
Hill Plots ◽  
Very High

1. Oxygen dissociation curves of the whole blood of larvae and adults of the Southern Hemisphere lamprey Geotria australis have been determined between pH 6.8 and 8.2 at 5, 15 and 25 degrees C. 2. The P50's at temperatures of 5, 15 and 25 degrees C and a pH of 7.75 were respectively 0.57, 0.92 and 1.19 mmHg in larvae and 6.9, 10.3 and 19.0 mmHg in adults. 3. The relatively very high affinity of larval blood for oxygen may reflect an adaptation to low environmental oxygen tensions. 4. The Bohr shift was not significantly affected by either temperature or life-cycle stage. 5. The slope (n) in Hill plots increased with temperature and oxygen saturation, and was greater in adults than in larvae.

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