Expression of epithelial alkaline phosphatase in segmentally iterated bands during grasshopper limb morphogenesis

Development ◽  
1993 ◽  
Vol 118 (2) ◽  
pp. 651-663 ◽  
Author(s):  
W.S. Chang ◽  
K.R. Zachow ◽  
D. Bentley
Keyword(s):  
Alkaline Phosphatase ◽  
Phospholipase C ◽  
Broad Band ◽  
Polyclonal Antiserum ◽  
Glycosyl Phosphatidylinositol ◽  
Limb Morphogenesis ◽  
Definition Of ◽  
Almost All ◽  
Source Of Information ◽  
Embryonic Pattern Formation

Although the study of rostral-caudal segmentation of the insect body has been a rich source of information about embryonic pattern formation, relatively little is known of the process of proximal-distal segmentation of insect appendages. Here we demonstrate that during the period of limb segmentation, five segmentally iterated, sharply demarcated bands of cell surface alkaline phosphatase activity are expressed in embryonic grasshopper limbs. These bands span each intersegmental boundary in the limb as well as one boundary within the tarsus. Within appendages, expression is restricted to epithelial cells, where activity is present on both apical and basolateral surfaces. This epithelial alkaline phosphatase remains active at neutral pH, is insensitive to levamisole inhibition, and is strongly inhibited by nucleoside monophosphates. Treatment of embryos with phosphatidylinositol-specific phospholipase C releases almost all visible chromogenic activity, indicating that the epithelial alkaline phosphatase is anchored to the plasma membrane by glycosyl-phosphatidylinositol. When material released by phosphatidylinositol-specific phospholipase C is separated on native polyacrylamide gels, a single broad band of enzymatic activity is detected following incubation with substrate. A polyclonal antiserum raised against a 55 × 10(3) M(r) alkaline phosphatase from shrimp recognizes a single band of 56 × 10(3) M(r) on immunoblots of grasshopper membrane proteins. The spatially restricted expression of epithelial alkaline phosphatase suggests that it may be involved in epithelial cell rearrangements or shape changes associated with limb segmentation and morphogenesis. It also may contribute to definition of axon routes in the limb, since pioneer afferent growth cones turn at, and migrate along, the edge of one alkaline phosphatase-expressing epithelial domain.

scholarly journals Activation of the glycosyl-phosphatidylinositol-anchored membrane dipeptidase upon release from pig kidney membranes by phospholipase C

1994 ◽  
Vol 303 (2) ◽  
pp. 633-638 ◽  
Author(s):  
I A Brewis ◽  
A J Turner ◽  
N M Hooper
Keyword(s):  
Staphylococcus Aureus ◽  
Phospholipase C ◽  
Active Site ◽  
Enzymic Activity ◽  
Polyclonal Antiserum ◽  
Gpi Anchor ◽  
Glycosyl Phosphatidylinositol ◽  
Pig Kidney ◽  
Conformational Constraints ◽  
Maximal Activation

Incubation of pig kidney microvillar membranes with Bacillus thuringiensis or Staphylococcus aureus phosphatidylinositol-specific phospholipase C (PI-PLC) resulted in the release of a number of glycosyl-phosphatidylinositol (GPI)-anchored hydrolases, including alkaline phosphatase (EC 3.1.3.1), amino-peptidase P (EC 3.4.11.9), membrane dipeptidase (EC 3.4.13.19), 5′-nucleotidase (EC 3.1.3.5) and trehalase (EC 3.2.1.28). Of these five ectoenzymes only for membrane dipeptidase was there a significant (approx. 100%) increase in enzymic activity upon release from the membrane. Maximal activation occurred at a PI-PLC concentration 10-fold less than that required for maximal release. In contrast solubilization of the membranes with n-octyl beta-D-glucopyranoside had no effect on the enzymic activity of membrane dipeptidase. A competitive e.l.i.s.a. with a polyclonal antiserum to membrane dipeptidase indicated that the increase in enzymic activity was not due to an increase in the amount of membrane dipeptidase protein. Although PI-PLC cleaved the GPI anchor of the affinity-purified amphipathic form of pig membrane dipeptidase there was no concurrent increase in enzymic activity. In the absence of PI-PLC, membrane dipeptidase in the microvillar membranes hydrolysed Gly-D-Phe with a Km of 0.77 mM and a Vmax. of 602 nmol/min per mg of protein. However, in the presence of a concentration of PI-PLC which caused maximal release from the membrane and maximal activation of membrane dipeptidase the Km was decreased to 0.07 mM while the Vmax. remained essentially unchanged at 624 nmol/min per mg of protein. Overall these results suggest that cleavage by PI-PLC of the GPI anchor on membrane dipeptidase may relax conformational constraints on the active site of the enzyme which exist when it is anchored in the lipid bilayer, thus resulting in an increase in the affinity of the active site for substrate.

Prawne regulacje pobierania i transplantacji narządów oraz tkanek w ujęciu europejskiej konwencji bioetycznej

2016 ◽  
pp. 52-65
Author(s):  
Patryk Kołodyński ◽  
Paulina Drab
Keyword(s):  
Ex Vivo ◽  
Legal Aspects ◽  
European Convention ◽  
The Public ◽  
Additional Protocol ◽  
The Past ◽  
Reliable Source ◽  
International Legal Order ◽  
Definition Of ◽  
Source Of Information

Over the past several years, transplantology has become one of the fastest developing areas of medicine. The reason is, first and foremost, a significant improvement of the results of successful transplants. However, much controversy arouse among the public, on both medical and ethical grounds. The article presents the most important concepts and regulations relating to the collection and transplantation of organs and tissues in the context of the European Convention on Bioethics. It analyses the convention and its additional protocol. The article provides the definition of transplantation and distinguishes its types, taking into account the medical criteria for organ transplants. Moreover, authors explained the issue of organ donation ex vivo and ex mortuo. The European Convention on Human Rights and Biomedicine clearly regulates the legal aspects concerning the transplantation and related basic concepts, and therefore provides a reliable source of information about organ transplantation and tissue. This act is a part of the international legal order, which includes the established codification of bioethical standards.

scholarly journals Frege’s puzzle and the ex ante Pareto principle

2020 ◽  
Author(s):  
Anna Mahtani
Keyword(s):  
Policy Choice ◽  
Choice Situation ◽  
Pareto Principle ◽  
Social Situations ◽  
Central Importance ◽  
Ex Ante ◽  
Definition Of ◽  
Almost All ◽  
Rational Behaviour ◽  
Fixed Population

Abstract The ex ante Pareto principle has an intuitive pull, and it has been a principle of central importance since Harsanyi’s defence of utilitarianism (to be found in e.g. Harsanyi, Rational behaviour and bargaining equilibrium in games and social situations. CUP, Cambridge, 1977). The principle has been used to criticize and refine a range of positions in welfare economics, including egalitarianism and prioritarianism. But this principle faces a serious problem. I have argued elsewhere (Mahtani, J Philos 114(6):303-323 2017) that the concept of ex ante Pareto superiority is not well defined, because its application in a choice situation concerning a fixed population can depend on how the members of that population are designated. I show in this paper that in almost all cases of policy choice, there will be numerous sets of rival designators for the same fixed population. I explore two ways that we might complete the definition of ex ante Pareto superiority. I call these the ‘supervaluationist’ reading and the ‘subvaluationist’ reading. I reject the subvaluationist reading as uncharitable, and argue that the supervaluationist reading is the most promising interpretation of the ex ante Pareto principle. I end by exploring some of the implications of this principle for prioritarianism and egalitarianism.

scholarly journals “There must be Someone’s Name Under Every Bit of Text, Even if it is Unimportant or Incorrect”: Plagiarism as a Learning Strategy

2021 ◽  
Author(s):  
Beata Bielska ◽  
Mateusz Rutkowski
Keyword(s):  
Higher Education ◽  
Detection Rate ◽  
Learning Strategy ◽  
Plagiarism Detection ◽  
International Context ◽  
Detection Systems ◽  
Uniform Definition ◽  
Definition Of ◽  
Difficult Situations ◽  
Source Of Information

AbstractThe article offers analyses of the phenomenon of copying (plagiarism) in higher education. The analyses were based on a quantitative survey using questionnaires, conducted in 2019 at one of the Polish universities. Plagiarism is discussed here both as an element of the learning process and a subject of public practices. The article presents students’ definitions of plagiarism, their strategies for unclear or difficult situations, their experiences with plagiarism and their opinions on how serious and widespread this phenomenon is. Focusing on the non-plagiarism norm, that is the rule that students are not allowed to plagiarize, and in order to redefine it we have determined two strategies adopted by students. The first is withdrawing in fear of making a mistake (omitting the norm), which means not using referencing in unclear situations, e.g. when the data about the source of information are absent. The second is reducing the scope of the norm applicability (limiting the norm), characterized by the fact that there are areas where the non-plagiarism norm must be observed more closely and those where it is not so important, e.g. respondents classify works as credit-level and diploma-level texts, as in the credit-level work they “can” sometimes plagiarize since the detection rate is poor and consequences are not severe. The presented results are particularly significant for interpreting plagiarism in an international context (no uniform definition of plagiarism) and for policies aimed at limiting the scale of the phenomenon (plagiarism detection systems1).

scholarly journals Purification and characterization of a major glycoprotein in rat hepatoma plasma membranes. One of the membrane proteins released by phosphatidylinositol-specific phospholipase C

1987 ◽  
Vol 241 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Y Ikehara ◽  
Y Hayashi ◽  
S Ogata ◽  
A Miki ◽  
T Kominami
Keyword(s):  
Alkaline Phosphatase ◽  
Phospholipase C ◽  
Plasma Membranes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Soluble Form ◽  
Microsomal Membranes ◽  
Hydrophobic Nature ◽  
Rat Hepatoma

A major glycoprotein of rat hepatoma plasma membranes was selectively released as a soluble form by incubating the membrane with phosphatidylinositol-specific phospholipase C. The soluble form corresponding to the glycoprotein was also prepared by butan-1-ol extraction of microsomal membranes at pH 5.5, whereas extraction at pH 8.5 yielded an electrophoretically different form with a hydrophobic nature. The soluble glycoprotein extracted at pH 5.5 was purified by sequential chromatography on concanavalin A-Sepharose, Sephacryl S-300 and anti-(alkaline phosphatase) IgG-Sepharose, the last step being used to remove a contaminating alkaline phosphatase. The glycoprotein thus purified was a single protein with Mr 130,000 in SDS/polyacrylamide-gel electrophoresis, although it behaved as a dimer in gel filtration on Sephacryl S-300. The glycoprotein was analysed for amino acid and carbohydrate composition. The composition of the carbohydrate moiety, which amounted to 64% by weight, suggested that the glycoprotein contained much larger numbers of N-linked oligosaccharide chains than those with O-linkage. It was confirmed that the purified glycoprotein was immunologically identical not only with that released by the phospholipase C but also with the hydrophobic form extracted with butan-1-ol at pH 8.5. The results indicate that the glycoprotein of rat hepatoma plasma membranes, which has an unusually high content of carbohydrate, is another membrane protein released by phosphatidylinositol-specific phospholipase C, as documented for alkaline phosphatase, acetylcholinesterase and Thy-1 antigen.

Evidence for glycosyl-phosphatidylinositol anchoring of Toxoplasma gondii major surface antigens

1989 ◽  
Vol 9 (10) ◽  
pp. 4576-4580
Author(s):  
S Tomavo ◽  
R T Schwarz ◽  
J F Dubremetz
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Toxoplasma Gondii ◽  
Phospholipase C ◽  
Surface Antigens ◽  
Water Soluble ◽  
Radioactive Label ◽  
Glycosyl Phosphatidylinositol ◽  
Major Surface

The four major surface antigens of Toxoplasma gondii tachyzoites (P43, P35, P30, and P22) were made water soluble by phosphatidylinositol-specific phospholipase C (PI-PLC). These antigens were biosynthetically labeled with 3H-fatty acids, [3H]ethanolamine, and [3H]carbohydrates. Treatment of 3H-fatty-acid-labeled parasite lysates with PI-PLC removed the radioactive label from these antigens. A cross-reacting determinant was exposed on these antigens after PI-PLC treatment.

scholarly journals Legal status of cryptocurrency in Asian countries

2021 ◽  
Vol 66 ◽  
pp. 96-102
Author(s):  
V.M. Logoida
Keyword(s):  
Civil Rights ◽  
Government Regulation ◽  
Legal Status ◽  
Legal Regulation ◽  
Intangible Asset ◽  
Asian Countries ◽  
Legal Nature ◽  
Liberal Approach ◽  
Definition Of ◽  
Almost All

The article is devoted to the study of the experience of legal regulation of the legal status of cryptocurrencies and transactions with them in Asian countries (except for the People's Republic of China and Asian countries - members of the Commonwealth of Independent States, as the author examined them in separate publications). In the article the author, based on the study of regulations, administrative and judicial practice of all major countries in this part of the world, emphasizes the divergent trends in cryptocurrency transactions regulation in the region, when some countries move from a liberal approach to the use of cryptocurrencies to their total ban and vice versa. It is noted that almost all countries in the region give a legal assessment of the payment function of cryptocurrencies, using regulatory or prohibitive approaches, depending on the chosen policy, which indirectly confirms their understanding of the legal nature of cryptocurrencies primarily as a means of payment. At the same time, these countries not only categorically distinguish cryptocurrencies from fiat money issued by central banks, but also mostly avoid the official definition of cryptocurrency as private (decentralized) cash, preferring to qualify them as an intangible asset, virtual asset, digital asset, financial value and even a good or service, which is currently a kind of compromise between political expediency and economic realities. The author also notes that the Asian region is characterized by very active attempts to resolve the legal status of cryptocurrencies at the legislative level, and not just administrative or judicial response to the actual legal relationship, although the progress of different countries in this matter is different. As a result, the author concludes that in the Asian countries considered in the article, there is no same view on the legal nature of cryptocurrency, its qualification as an object of civil rights, and ways to regulate transactions with it (libertarian approach, positive-cryptocurrency approach but with detailed government regulation and control or a completely restrictive policy in relation to the cryptocurrency market).

scholarly journals The Tax Cuts and Jobs Act and the Middle Class

2019 ◽  
Vol 26 (01) ◽  
pp. 53
Author(s):  
Deborah Combs ◽  
Brian Nichols
Keyword(s):  
Middle Class ◽  
The United States ◽  
Census Bureau ◽  
Tax Rates ◽  
United States Census ◽  
United States Census Bureau ◽  
Definition Of ◽  
Almost All ◽  
Jobs Act ◽  
Tax Cuts

This paper explores how the tax cuts and jobs act of 2017 impacts middle-class taxpayers by calculating the tax liability at different levels of income and deductions in 2017 versus 2018. The results confirm the statements supporting the positive effect of the tax change for the middle class. The tax cut and jobs act eliminates personal exemptions, changes the standard deductions at various incomes and family sizes, and lowers marginal tax rates. After providing details of the act, this research examines the definition of the U.S. middle class by using prior research from the Pew Research Center, the United States Census Bureau, and the federal reserve to determine which income levels are attributable to the middle class. Then the tax liability for these income classes is calculated for single and married filing jointly taxpayers in both 2017 and 2018 to determine if the tax cuts and jobs act reduces the tax liability for the middle class. The results show that in almost all scenarios the tax liability in 2018 will be lower than in 2017, regardless of whether standard or itemized deductions are taken. The marriage penalty is no longer applicable, and the new tax act provides a substantial benefit to large families

scholarly journals Defence strategies of the smaller NATO states – a comparative study

2020 ◽  
Vol 29 (4) ◽  
pp. 023-045
Author(s):  
Lukáš Dyčka ◽  
Taivo Rõkk ◽  
Zdzisław Śliwa
Keyword(s):  
Comparative Study ◽  
Second Step ◽  
Small State ◽  
Level Of Details ◽  
Definition Of ◽  
Defence Strategies ◽  
Source Of Information ◽  
National Defence

Defence strategies of smaller NATO states represent interesting source of information about defence policies of this pool of countries. Definition of what constitutes "small state" is discussed in first step. In second step, this study compares 10 selected NATO countries Defence Strategies in terms of identified risks and threats, future military capabilities to counter threats, processes of drafting defence papers, level of details and approving authorities. Outlining these indicators and characteristics provide useful overview for future draft of National defence strategies within countries of similar size.

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