Thromboxane Synthase Has the Same Pattern of Expression as Platelet Specific Glycoproteins during Human Megakaryocyte Differentiation

2000 ◽  
Vol 83 (05) ◽  
pp. 759-768 ◽  
Author(s):  
Natacha Vitrat ◽  
Rémi Letestu ◽  
Aline Massé ◽  
Vladimir Lazar ◽  
Najet Debili ◽  
...  

SummaryRegulation of the platelet formation process is poorly understood. It has been shown that p45NF-E2 deficient mice have a profound defect in platelet formation and recently the first platelet/megakaryocytic gene regulated by NF-E2, thromboxane synthase (TXS), has been identified. In this study, we investigated TXS expression as a model of a gene regulated by NF-E2 during MK differentiation. Megakaryocytic cells derived from blood CD34+ cells were purified according to their stage of maturation on the basis of expression of CD34, CD41a and CD42a, permitting to define different stages in MK differentiation. By means of real-time quantitative RT-PCR, we could determine that the level of TXS increased during differentiation in parallel with the expression of c-mpl and GPIIb (CD41). However, amounts of TXS transcripts increased about 1.6-fold more than that of GPIIb or c-mpl transcripts during maturation. Expression of TXS and MK specific proteins such as CD41a, CD42a and vWF was also correlated in maturing MKs. In addition, staining by anti-TXS antibody of proplatelet bearing MKs was not increased in comparison to that observed in mature MK, suggesting that TXS is not upregulated during platelet formation. In addition, we investigated whether TXS and cyclooxygenase could be involved in platelet formation by adding aspirin into the cultures. No significant decrease of platelet production was observed.In conclusion, this study shows that TXS is coordinately expressed with the other platelet proteins during MK differentiation but is not directly involved in platelet formation.

Author(s):  
Anaïs Pongerard ◽  
Lea Mallo ◽  
Christian Gachet ◽  
Henri de La Salle ◽  
François Lanza ◽  
...  

2002 ◽  
Vol 2 (3) ◽  
pp. 17-22
Author(s):  
A.P. Wyn-Jones ◽  
J. Watkins ◽  
C. Francis ◽  
M. Laverick ◽  
J. Sellwood

Two rural spring drinking water supplies were studied for their enteric virus levels. In one, serving about 30 dwellings, the water was chlorinated before distribution; in the other, which served a dairy and six dwellings the water was not treated. Samples of treated (40 l) and untreated (20 l) water were taken under normal and heavy rainfall conditions over a six weeks period and concentrated by adsorption/elution and organic flocculation. Infectious enterovirus in concentrates was detected in liquid culture and enumerated by plaque assay, both in BGM cells, and concentrates were also analysed by RT-PCR. Viruses were found in both raw water supplies. Rural supplies need to be analysed for viruses as well as bacterial and protozoan pathogens if the full microbial hazard is to be determined.


Blood ◽  
1987 ◽  
Vol 69 (2) ◽  
pp. 522-528 ◽  
Author(s):  
M Tong ◽  
P Seth ◽  
DG Penington

Abstract The process of platelet formation by the fragmentation of megakaryocyte pseudopodia, termed proplatelets, demonstrable in the marrow sinusoids is poorly understood. “Stress” platelets produced under conditions of stimulated platelet production differ from normal circulating platelets with respect to volume and a number of functional characteristics. To clarify the relationship of stress platelets to proplatelets, rats were injected with heterologous platelet antiserum. Nondiscoid platelet forms, some characteristically beaded in appearance, strongly resembling bone marrow proplatelets, can be recovered in the circulation of normal rats. During the early period of recovery from acute thrombocytopenia, there was a substantial increase in the proportion of these elongated platelets in the citrated platelet rich plasma. Exposure to EDTA rendered them spherical. Circulating proplatelets may contribute significantly to the prompt increase in platelet volume during recovery from acute thrombocytopenia at a time prior to significant increase in megakaryocyte size and ploidy.


Coronaviruses ◽  
2021 ◽  
Vol 02 ◽  
Author(s):  
Latifa Khattabi ◽  
Mustapha Mounir Bouhenna ◽  
Feriel Sellam

: The present paper elucidates the conceivable application of two key molecules in SARS-CoV-2 detection of suspected infected persons. These molecules were selected from the basis of ACE-2 and S protein strong interaction that allows virus attachment to its host cells, on the other hand specific immunocompetant effectors generated by human immune system during the infection. Several testing procedures are already used to diagnose SARS-CoV-2 infection, particularly RT-PCR technique. ELISA and LFIA are possible assays for the employment of shACE-2/ hAc-anti-S (the molecules of interest) as the main agents of the test and confer a dual principal functions (capture and detection). The future diagnostic kits involving shACE-2 and hAc-anti-S will have the particularity of high sensitivity and rapid detection in addition to its advantage of relatively easy conception. It could be largely considered as a technical advanced kits in regards to the current SARS-CoV-2 diagnostic immunoassays.


Stem Cells ◽  
1998 ◽  
Vol 16 (S1) ◽  
pp. 31-36 ◽  
Author(s):  
Qi Chen ◽  
Frederic J. De SAUVAGE ◽  
Gregg Solar ◽  
Dan L. Eaton

2020 ◽  
Author(s):  
Chun-Hao Su ◽  
Wei-Ju Liao ◽  
Wei-Chi Ke ◽  
Ruey-Bing Yang ◽  
Woan-Yuh Tarn

SUMMARYThrombocytopenia-absent radius syndrome is caused by a deletion in chromosome 1q21.1 in trans with RBM8A mutations in the noncoding regions. We generated megakaryocyte-specific Rbm8a knockout (Rbm8aKOMK) mice that exhibited marked thrombocytopenia, internal hemorrhage, and splenomegaly, indicating a disorder of platelet production. Rbm8aKOMK mice accumulated immature megakaryocytes in the bone marrow and spleen. Depletion of Y14/RBM8A in human erythroleukemia (HEL) cells inhibited phorbol ester-induced polyploidy and downregulated the signaling pathways associated with megakaryocyte maturation. Accordingly, Rbm8aKOMK mice had reduced expression of surface glycoproteins on platelets and impaired coagulation. Moreover, p53 level was increased in Y14-depleted HEL cells and Rbm8aKOMK megakaryocytes. Treatment with a p53 inhibitor restored ex vivo differentiation of Rbm8aKOMK megakaryocytes and unexpectedly activated Y14 expression in HEL cells. Knockout of Trp53 in part restored the platelet count of Rbm8aKOMK mice. These results indicate that the Y14-p53 circuit plays a critical role in megakaryocyte differentiation and platelet production.


2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Pamela Loindong ◽  
Gayda Bachmid ◽  
Djeinnie Imbang

Language is a means of human communication through social interaction with others. According to Chomsky, language is a collection of sentences, each with a certain length and built by a set of specific elements. Language is a regular system from various forms of sounds used in expressing thoughts and feelings of the users of the language. Indonesian language was born on October 28, 1928, grew and developed from the Malay language since ancient times, and has been used as a lingua franca not only in the archipelago, but also in almost all of Southeast Asia. This study examines the language based on the internal object of linguistic study; micro linguistic and one of its sub-discipline is morphology, focused on forms of acronyms used in UPTD Balai Peralatan dan Perbekalan Dinas Pekerjaan Umum Provinsi Sulawesi Utara. The research focus is on the forms of acronyms used in UPTD Balai Peralatan dan Perbekalan Dinas Pekerjaan Umum Provinsi Sulawesi Utara. There are three forms of acronyms used by the Aparatur Sipil Negera (Civil Servant) and Tenaga Harian Lepas (Intern) on UPTD Balai Peralatan dan Perbekalan Dinas Pekerjaan Umum Provinsi Sulawesi Utara, which is acronym whose form is determined by the formation process based on the theory of O'Grady, Dobrovolsky, theory of Kridalaksana. H., and one of the form does not follow the two existing theories. Of the thirty two acronyms found, twenty nine are formal acronyms in Indonesian language and the other three are informal acronyms.  


2018 ◽  
Vol 23 (21) ◽  
Author(s):  
Emma Oliosi ◽  
Chantal Serero Corcos ◽  
Paulo Feijo Barroso ◽  
Alexandre Bleibtreu ◽  
Gilda Grard ◽  
...  

We report two yellow fever cases in unvaccinated French travellers in Brazil in January and March 2018, respectively; one exposed during an excursion in Minas Gerais and the other in Ilha Grande. Both presented with fever, hepatitis, thrombocytopenia and leucopenia. Yellow fever diagnosis was based on RT-PCR and serological tests. Both patients recovered within a few days. The increasing occurrence of cases in unvaccinated travellers highlights the need to reinforce vaccination recommendation for travellers at-risk.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
D Mataro ◽  
I Cuevas-Saiz ◽  
J A Castilla ◽  
J A Dominguez ◽  
N Prados ◽  
...  

Abstract Study question What is the SARS-CoV-2 positivity rate following the Spanish Fertility Society (SEF)/Association for the Study of Reproductive Biology (ASEBIR) screening recommendations? Summary answer The SARS-CoV-2 positivity rate in the centers following the SEF/ASEBIR screening recommendations was 0.316% after the first survey and 0.364% after the second one What is known already Due to the Sars-Cov-2 pandemic, all the Medical Assisted Reproduction (MAR) centers in Spain had to interrupt their activity most of the time during the first pandemic wave. On April 27th activity was restarted, and SEF and ASEBIR jointly elaborated a guide describing their SARS-CoV-2 screening recommendations for MAR centers. This document aims to achieve a safe environment for patients and staff. It includes the possibility of screening patients through a targeted clinical interview and the use of reverse-transcriptase polymerase chain reaction (RT-PCR). The aim of this study is to quantify the SARS-CoV-2 positivity rate based on these recommendations. Study design, size, duration National multicenter cross-sectional study. Information was gathered from centers using an anonymous survey asking for aggregated data about the number of positive cases among screened patients, sent twice. The first survey covered the period April 27th - June 30th. Second survey covered July 1st - August 31st. Response rates among centres were 9% (29/319) and 6% (20/319), respectively. This study includes 2,695 and 4,068 screenings performed in the first and the second survey, respectively. Participants/materials, setting, methods The SEF/ASEBIR recommendations describe two screening strategies. Strategy (a) consists in a targeted clinical interview (TCI) evaluating clinical symptoms and exposure risk, first before starting the cycle, and before egg-retrieval, intrauterine insemination (IUI), and/or embryo transfer (ET). Suspicious cases could be confirmed by further RT-PCR testing. Strategy (b) consists in conducting the same first TCI, and a systematic RT-PCR testing before the medical procedure in all patients. All patients in both strategies have a TCI. Main results and the role of chance In the 1st survey, 1,177 screenings and 919 RT-PCR (78.07%) were performed before the egg-retrieval. One patient with a negative TCI and positive RT-PCR was detected, and the cycle was cancelled. 1,518 screenings and 1,161 RT-PCRs (76.48%) were performed before the ET/IUI. Two patients with a positive TCI were detected, one did not perform a RT-PCR, while the other resulted in a positive RT-PCR. Both cycles were cancelled. Besides, 5 patients with negative TCI performed a RT-PCR with a positive result; all 5 were cancelled. Overall, the SARS-CoV-2 positivity rate was 8/2533 (0.316%), of which 7/2533 (0.276%) were identified by RT-PCR testing. The 2nd survey included 1,376 screenings and 1,009 RT-PCR (73.32%) performed before the egg-retrieval. Four patients with negative TCI and further positive RT-PCR were detected, and their cycle was cancelled. 2,692 screenings and 2,134 RT-PCR (79.27%) were performed before ET/IUI. Two patients had a positive TCI, one with a negative, the other with a positive RT-PCR testing; both cycles were cancelled. Besides, 8 patients with negative TCI, but positive RT-PCR testing, were detected and their cycles cancelled. Overall, the SARS-CoV-2 positivity rate was 14/3846 (0.364%), of which 13/3846 (0.338%) after positive RT-PCR testing. Limitations, reasons for caution The criteria for performing the RT-PCR testing were not the same in all MAR Centres or even in the same centre at different times. Due to the low response rate of the study, we should not extend these results to all the MAR Centres in Spain. Wider implications of the findings The results of the surveys suggest that the SEF/ASEBIR recommendations could be a good screening strategy for SARS-Cov-2 at MAR Centres. Further survey collected at different times of the pandemic are warranted, including new strategies for screening as antigen tests or vaccination status. Trial registration number Not applicable


Cell Cycle ◽  
2017 ◽  
Vol 16 (10) ◽  
pp. 979-990 ◽  
Author(s):  
Ankita Dhenge ◽  
Kedar Limbkar ◽  
Sameer Melinkeri ◽  
Vaijayanti Prakash Kale ◽  
Lalita Limaye

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