New biological concepts on coagulation inhibitors

1993 ◽  
Vol 19 (S1) ◽  
pp. S3-S7 ◽  
Author(s):  
N. Sala ◽  
J. Fontcuberta ◽  
M. LL. Rutllant
Keyword(s):  
Coagulation Inhibitors ◽  
Biological Concepts

Extrinsic Pathway Inhibitor in Elective Surgery: A Comparison with other Coagulation Inhibitors

1989 ◽  
Vol 62 (03) ◽  
pp. 856-860 ◽  
Author(s):  
P M Sandset ◽  
H E Høgevold ◽  
T Lyberg ◽  
T R Andersson ◽  
U Abildgaard
Keyword(s):  
Vascular Surgery ◽  
Protein C ◽  
Elective Surgery ◽  
Perioperative Period ◽  
Acute Phase Reactant ◽  
Hip Surgery ◽  
Albumin Concentration ◽  
Extrinsic Pathway ◽  
Heparin Cofactor Ii ◽  
Coagulation Inhibitors

SummaryExtrinsic coagulation pathway inhibitor may be an important regulator of haemostasis to prevent thrombosis after tissue damage. The functional activity of this inhibitor was determined using a chromogenic substrate assay, and compared to the activities of anti thrombin, heparin cofactor II and protein C during the perioperative period of elective hip replacement (n = 28), cholecystectomy (n = 11), and vascular surgery (n = 5). Peroperatively, all the inhibitors decreased rather similarly and to the same degree as the decrease in albumin concentration. The decreases during hip surgery were about 2-fold the decreases observed during cholecystectomy. A significant peroperative increase in extrinsic pathway inhibitor activity was observed in vascular surgery, probably due to a bolus injection of heparin. Antithrombin, heparin cofactor II and protein C levels normalized on days 3-5 postoperatively in all three patient groups. Sustained low levels of extrinsic pathway inhibitor were observed on postoperative days 1 to 7 in hip surgery patients. Apparently, extrinsic pathway inhibitor is not an acute phase reactant. In uncomplicated surgery, the decreases of the coagulation inhibitor levels are mainly due to hemodilution.

The estimation of the nutritive value of feeds as energy sources for ruminants and the derivation of feeding systems

1978 ◽  
Vol 90 (1) ◽  
pp. 47-68 ◽  
Author(s):  
K. L. Blaxter ◽  
A. W. Boyne
Keyword(s):  
Organic Matter ◽  
Nutritive Value ◽  
Metabolizable Energy ◽  
Crude Fibre ◽  
Mitscherlich Equation ◽  
Energy Retention ◽  
Gross Energy ◽  
Biological Concepts ◽  
Two Parameters ◽  
Feeding Systems

SUMMARYThe results of 80 calorimetric experiments with sheep and cattle, mostly conducted in Scotland, were analysed using a generalization of the Mitscherlich equation R = B(l–exp(–pG))–l, where R is daily energy retention and G daily gross energy intake, both scaled by dividing by the fasting metabolism. The relations between gross energy and metabolizable energy were also examined. Methods of fitting the Mitscherlich equation and the errors associated with it are presented.It is shown that the gross energy of the organic matter of feed can be estimated from proximate principles with an error of ±2·3% (coefficient of variation) and that provided different classes of feed are distinguished, the metabolizable energy of organic matter can be estimated from gross energy and crude fibre content with an error of ±6·9%. Parameters of the primary equation made with cattle agreed with those made with sheep and there was no evidence of non-proportionality of responses on substitution of feeds in mixtures.The efficiency of utilization of gross energy for maintenance and for body gain of energy was related to the metabolizability of gross energy and, in addition, to fibre or to protein content. Prediction equations are presented which describe these relationships.It is shown that the primary equation can be manipulated to express a number of biological concepts and that its two parameters B and p can be simply derived from estimates of the two efficiency terms for maintenance and production.The results are discussed in relation to the design of feeding systems for ruminant animals and to the derivation of optima in their feeding.

Molecular Oncology for the Head and Neck Surgeon

1995 ◽  
Vol 112 (5) ◽  
pp. P88-P89
Author(s):  
Norris K. Lee
Keyword(s):  
Head And Neck Cancer ◽  
Molecular Biology ◽  
Cancer Treatment ◽  
Head And Neck ◽  
Neck Cancer ◽  
Cancer Model ◽  
Educational Objectives ◽  
Molecular Oncology ◽  
The Future ◽  
Biological Concepts

Educational objectives: To understand basic molecular biological concepts and breakthroughs as they apply to the head and neck cancer model and to envision the future of head and neck cancer treatment, within the context of molecular biology.

Component Analysis: An Aid to the Interpretation of Data

1969 ◽  
Vol 5 (2) ◽  
pp. 151-164 ◽  
Author(s):  
D. A. Holland
Keyword(s):  
Principal Component Analysis ◽  
Statistical Study ◽  
Principal Component ◽  
Component Analysis ◽  
Linear Functions ◽  
Analysis Approach ◽  
Specific Technique ◽  
Mathematical Technique ◽  
Biological Concepts ◽  
General Component

SummaryPrincipal component analysis is a mathematical technique for summarizing a set of related measurements as a set of derived variates, frequently fewer in number, which are definable as independent linear functions of the original measurements. Consideration of their mathematical nature shows that they do not, themselves, necessarily correspond to sensible biological concepts, though they are more amenable to statistical study than the original measurements. Further, by assessing the extent to which they are in accordance with biological hypotheses, or with the results of other, similar, analyses, they can be transformed into other linear functions which are meaningful in the biological sense, or consistent with other results. Thus the specific technique of principal component analysis is developed into a more general component analysis approach. With proper regard for the purpose the analysis is intended to serve and for the mathematical restrictions involved, this approach can lead to a useful condensation of a mass of data, a better under-standing of the observed individuals as entities rather than collections of isolated measurements, and to the formulation of new hypotheses for subsequent examination.

scholarly journals On the modeling of the interaction between tumor growth and the immune system using some new fractional and fractional-fractal operators

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Behzad Ghanbari
Keyword(s):  
Immune System ◽  
Infectious Diseases ◽  
Tumor Growth ◽  
Computational Models ◽  
Recent Literature ◽  
Approximate Solutions ◽  
Biological Phenomena ◽  
Uniqueness Of The Solution ◽  
Biological Concepts ◽  
New Research

Abstract Humans are always exposed to the threat of infectious diseases. It has been proven that there is a direct link between the strength or weakness of the immune system and the spread of infectious diseases such as tuberculosis, hepatitis, AIDS, and Covid-19 as soon as the immune system has no the power to fight infections and infectious diseases. Moreover, it has been proven that mathematical modeling is a great tool to accurately describe complex biological phenomena. In the recent literature, we can easily find that these effective tools provide important contributions to our understanding and analysis of such problems such as tumor growth. This is indeed one of the main reasons for the need to study computational models of how the immune system interacts with other factors involved. To this end, in this paper, we present some new approximate solutions to a computational formulation that models the interaction between tumor growth and the immune system with several fractional and fractal operators. The operators used in this model are the Liouville–Caputo, Caputo–Fabrizio, and Atangana–Baleanu–Caputo in both fractional and fractal-fractional senses. The existence and uniqueness of the solution in each of these cases is also verified. To complete our analysis, we include numerous numerical simulations to show the behavior of tumors. These diagrams help us explain mathematical results and better describe related biological concepts. In many cases the approximate results obtained have a chaotic structure, which justifies the complexity of unpredictable and uncontrollable behavior of cancerous tumors. As a result, the newly implemented operators certainly open new research windows in further computational models arising in the modeling of different diseases. It is confirmed that similar problems in the field can be also be modeled by the approaches employed in this paper.

Legislating Biological Concepts

Science ◽  
1968 ◽  
Vol 160 (3829) ◽  
pp. 717-717
Author(s):  
George E. Moore
Keyword(s):  
Biological Concepts

Can a Biology Course Rooted in the Tree of Life Overcome Student Misconceptions?

2016 ◽  
Vol 78 (2) ◽  
pp. 93-98
Author(s):  
John W. Doudna
Keyword(s):  
Tree Of Life ◽  
Student Comprehension ◽  
Student Misconceptions ◽  
Novel Approach ◽  
History Of Evolution ◽  
History Of ◽  
Course Material ◽  
Biological Concepts ◽  
Biology Curriculum ◽  
Common Misconceptions

Introductory biology for nonmajors provides an opportunity to engage students with the complexity of life. In these courses, instructors also have the opportunity to experiment with course material and delivery, especially with an intent to overcome common misconceptions about biology. Fortunately, frameworks exist that can be integrated into a completely novel classroom framework: the AP biology curriculum and the tree of life. In addition, assessments are available that specifically address common misconceptions. I tested whether such a novel approach, covering the four big ideas in biology equally and structured around an accurate depiction of biodiversity as a branching history of evolution, can improve student comprehension of difficult biological concepts. In the end, I found that students improved significantly in their understanding of biology and were much less likely to have common misconceptions about difficult topics.

The 536C→T Transition in the Human Tissue Factor Pathway Inhibitor (TFPI) Gene Is Statistically Associated with a Higher Risk for Venous Thrombosis

1999 ◽  
Vol 82 (07) ◽  
pp. 1-5 ◽  
Author(s):  
Michael Schmidt ◽  
Christian Götting ◽  
Britt Schwenz ◽  
Stefan Lange ◽  
Gert Müller-Berghaus ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Tissue Factor ◽  
Tissue Factor Pathway Inhibitor ◽  
Blood Donors ◽  
Amino Acid Position ◽  
Immunological Methods ◽  
Venous Thromboembolic ◽  
Coagulation Inhibitors ◽  
Tissue Factor Pathway

SummaryTissue factor pathway inhibitor (TFPI) is an important regulator in the extrinsic blood coagulation pathway. Although the regulatory biochemical role of TFPI is evident, the clinical significance of this proteinase inhibitor remains to be elucidated. The definition of a clinical TFPI deficiency seems to be more complex than that of other coagulation inhibitors because the activity and concentration of circulating TFPI can not be considered a true measure of in vivo levels. Its determination in plasma samples by immunological methods or functional assays has been shown to be inadequate in the detection of a clinical deficiency.Therefore, we screened genomic DNA samples of blood donors and thrombotic patients for alterations in the TFPI gene to assess the influence of a modified TFPI in venous thromboembolic diseases. We detected a single nucleotide substitution in exon 7 (536C→T) leading to a proline to leucine exchange at amino acid position 151 of the protein ([P151L]TFPI) and found the prevalence of heterozygous carriers in German unrelated blood donors to be 0.2% (n = 5120).Four unrelated persons out of 14 probands carrying the genetic variation could be linked to venous thrombosis. For calculation of a potential risk for venous thrombosis for carriers of the mutation we investigated healthy blood donors about thrombotic events. 7 out of 308 blood donors were found to have a history of venous thrombosis, one of them carried the TFPI mutation. Statistical calculation showed a significant relative risk for venous thrombosis for individuals with the trait (odds ratio, 9.3; confidence interval, 1.8-48.6; p <0.01).

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