Immunoelectron microscopy of frozen hydrated blood platelets

Author(s):  
E. T. O’Toole

We have previously shown that ultrarapid freezing followed by cryomicroscopy provides a uniquely effective preservation of platelet ultrastructure, particularly in its cytoskeleton and membrane systems. However, a limitation of cryomicroscopy of frozen hydrated specimens is the lack of information about the localization of specific proteins within the cell. Methods for immunolocalization of antigens on material that has been rapidly frozen, freeze-substituted and embedded in immunocompatible resins have excited considerable interest among biologists, because of the high quality of preservation afforded by fast-freezing techniques. However, the extent to which fixation and dehydration affect the distribution of antigens is not known. Here we describe a method for imaging immunolabeled cells in the frozen hydrated state, avoiding the destructive steps of dehydration.Blood platelets were isolated from citrated whole blood by differential centrifugation and washed in Hank’s balanced salts. Washed platelet suspensions were placed on formvar coated, carbon stabilized gold finder grids and placed in a humid chamber at 37°C for 30 minutes to allow adhesion and spreading of the cells.

Author(s):  
E. T. O'Toole ◽  
R. R. Hantgan ◽  
J. C. Lewis

Thrombocytes (TC), the avian equivalent of blood platelets, support hemostasis by aggregating at sites of injury. Studies in our lab suggested that fibrinogen (fib) is a requisite cofactor for TC aggregation but operates by an undefined mechanism. To study the interaction of fib with TC and to identify fib receptors on cells, fib was purified from pigeon plasma, conjugated to colloidal gold and used both to facilitate aggregation and as a receptor probe. Described is the application of computer assisted reconstruction and stereo whole mount microscopy to visualize the 3-D organization of fib receptors at sites of cell contact in TC aggregates and on adherent cells.Pigeon TC were obtained from citrated whole blood by differential centrifugation, washed with Ca++ free Hank's balanced salts containing 0.3% EDTA (pH 6.5) and resuspended in Ca++ free Hank's. Pigeon fib was isolated by precipitation with PEG-1000 and the purity assessed by SDS-PAGE. Fib was conjugated to 25nm colloidal gold by vortexing and the conjugates used as the ligand to identify fib receptors.


Author(s):  
B.A. Shinoda ◽  
M.D. Hardison ◽  
S.F. Mohammad ◽  
H.Y.K. Chuang ◽  
R.G. Mason

The utilization of blood platelets in experimentation frequently requires their separation from blood and subsequent resuspension in media of known composition. Several methods are available for preparation of isolated platelets (1-3) by differential centrifugation or gel filtration, but most methods are tedious and time consuming. Often platelets obtained by use of such methods are in a state different functionally and ultrastructurally from that of platelets in plasma (4).Recently Mohammad, Reddick, and Mason (5) reported a method in which platelets were separated from plasma by ADP-induced aggregation, washed several times, and then incubated in a carefully selected medium that resulted in deaggregation of platelets.


1963 ◽  
Vol 09 (03) ◽  
pp. 512-524 ◽  
Author(s):  
Chava Kirschmann ◽  
Sara Aloof ◽  
Andre de Vries

SummaryLysolecithin is adsorbed to washed blood platelets and, at sufficient concentration, lyses them, inhibits their clot-retracting activity and promotes their thromboplastin-generating activity. Lysolecithin adsorption to the platelet was studied by using P32-labelled lysolecithin obtained from the liver of rats injected with labelled orthophosphate. The amount of lysolecithin adsorbed to the surface of the washed platelet in saline medium is dependent on the concentration of lysolecithin in solution and reaches saturation — 5 × 10-8 jig per platelet — at a concentration of 9—10 µg per ml. Platelet lysis in saline medium begins at a lysolecithin concentration higher than 18 jig per ml. Plasma and albumin prevent adsorption of lysolecithin to the platelet and protect the platelet from damage by lysolecithin. Albumin is able to remove previously adsorbed lysolecithin from the platelet surface. The protective action of plasma explains the lack of platelet damage in blood, the plasma lecithin of which has been converted to lysolecithin by the action of Vipera palestinae venom phosphatidase, in vitro and in vivo.


Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.


2020 ◽  
pp. 52-58 ◽  
Author(s):  
A. A. Eryomenko ◽  
N. V. Rostunova ◽  
S. A. Budagyan ◽  
V. V. Stets

The experience of clinical testing of the personal telemedicine system ‘Obereg’ for remote monitoring of patients at the intensive care units of leading Russian clinics is described. The high quality of communication with the remote receiving devices of doctors, the accuracy of measurements, resistance to interference from various hospital equipment and the absence of its own impact on such equipment were confirmed. There are significant advantages compared to stationary patient monitors, in particular, for intra and out-of-hospital transportation of patients.


2018 ◽  
pp. 26-35
Author(s):  
Z. A. Agaeva ◽  
K. B. Baghdasaryan

The transthoracic echocardiography made by multifrequency probes with support of the mode of the second harmonic imaging, is a competitive method for visualization of the main coronary arteries and allows to estimate coronary blood flow with high quality. Of course, the method has considerable restrictions, most important of which is the low spatial resolution of a method, due to small acoustic window. Because of this the transthoracic visualization of coronary arteries perhaps will not become the leading method of anatomic reconstruction of separately taken coronary artery and especially all coronary arteries system. However uniqueness and indisputable advantage of this method is an opportunity to noninvasively estimate a coronary blood flow both once, and in dynamics.


2020 ◽  
Vol 18 (4) ◽  
pp. 739-752 ◽  
Author(s):  
R.M. Sadykov

Subject. This article deals with the issues of social justice and a high quality of life, creating favorable economic and social conditions. Objectives. The article aims to assess the rate and changes in poverty in Russia and the Republic of Bashkortostan and develop complementary measures to reduce it. Methods. For the study, I used the methods of logical, comparative, economic and statistical analyses, the results of sociological studies, and official statistics. Results. The article highlights additional measures to reduce poverty in the region, including the establishment of a minimum social standard of living in each particular region that determines the poverty rate. Conclusions. Various factors, such as economic sanctions, economic slowdowns, territorial and regional imbalances, lead to living standards decline and poverty rise.


Author(s):  
La Duc Minh ◽  
Nguyen Thi Hao ◽  
Vu Thi Thuy

Ethnic affairs play an important role in socio of ethnic groups’ solidarity, assurance of security and national defense stability. In -economic development, maintenanceorder to improve the quality of ethnic affairs, it is practical to carry out postgraduate training of officer implementing ethnic affairs using state budget with the aim of encouraging and enhancing officer quality to satisfy high-quality human resource in international integration.


2018 ◽  
Author(s):  
V.A. Borisov ◽  
A.M. Menshikh ◽  
V.S. Sosnov ◽  
G.F. Monakhos

Показано действие минеральных удобрений, микрокристаллического комплексного водорастворимого удобрения «Мастер» и органоминерального наноудобрения с ростостимулирующей активностью «Арксойл» при капельном орошении на урожайность и качество сладкого перца нового гибрида F1 Темп. Сочетание основного удобрения с листовой и корневой подкормками позволяет получить до 65 т/га плодов перца высокого качества.The action of mineral fertilizers, microcrystalline complex water soluble fertilizer Master and organic mineral nano-fertilizer with growth-stimulating activity Arksoil under drip irrigation on the productivity and quality of sweet pepper of the new hybrid F1 Temp is shown. The combination of basic fertilizer with leaf and root fertilizing allows to obtain up to 65 t/ha of pepper fruits of high quality.


2017 ◽  
Vol 5 (1) ◽  
pp. 498
Author(s):  
Maria Stănescu

The article is about the role of the family in the education and formation of children and, especially, in the life and development of autistic children. It describes the problems their family is facing and the need for counseling to parents with autistic children. The reaction to finding the diagnosis of autism varies from one family to another and may encounter a large variety: from disbelief, anger, guilt, helplessness, devastation, surprise, or even rejection of the child, to understanding and relief when finally the parents have an explanation for their child behaviors. Early intervention is important in psychological sustaining of the parent, as parent involvement in the recovery of the child with autism has a determinant role in his development and in ensuring a high quality of life of the child and the life of the hole family. The response to a child's autism diagnosis varies from one family to another. The family goes through a variety of disbelief, anger, guilt, helplessness, devastation, surprise, or even rejection of the child, to understanding and relief. Early intervention is very important in the psychological support of the parent. Because any change disturbs the family equilibrium. A diagnosis of autism changes not only the life of the diagnosed child, but also the life of family members. All the resources are focused on the need of the child. Although each parent is different, after diagnosing the child with autism, all parents are overwhelmed by confusion, shock and denial. Parents' feelings can be influenced by how their children's situation affects different aspects of life - it has an impact on service, on social life and all their personal life. If we look at the family as a system and when a disturbing factor appears, all parts of the system are affected. The involvement of parents in the recovery of the child with autism has a decisive role in its development and in ensuring a high quality of child's life and family life.


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