scholarly journals The Early Phase of Vascularization in Intraocular Telencephalic Transplants

1997 ◽  
Vol 6 (2) ◽  
pp. 97-103 ◽  
Author(s):  
Andrea Tuba ◽  
Mihály Kálmán
Keyword(s):  
Blood Vessels ◽  
Adult Rats ◽  
Direct Role ◽  
Thin Sections ◽  
Donor Tissue ◽  
Graft Tissue ◽  
Host Blood ◽  
To Receive ◽  
Tissue Defects

The present study focused on the early events of vascularization of intraocular cerebral transplants. Telencephalic pieces of rat embryos (El5) were transplanted into the anterior eye chamber of adult rats in deep ketamine-xylazine narcosis. At 3-, 4-, 5-, 6-, or 7-day postoperative survival periods, the rats were perfused and the transplants, with their iridic beds, were processed into serial, semi-thin sections, In 3- and 4-day transplants, neither dilated (perfused) nor collapsed blood vessels were found, but tissue defects, without proper wall and filled by non-nucleated (mature, host) erythrocytes, were seen. On post-operative day 5, large sinusoids were seen lines by endothel and free of blood cells (as a consequence of perfusion). On days 6 and 7, the usual, although large, blood vessels were found. Our results suggest that the critical period of transplant vascularization is between postoperative days 4 and 5, and that the original vessels of donor tissue degenerate and disappear during the first postoperative days and thus, do not participate directly in transplant vascularization. Our hypothesis is that vascular invasion begins with the opening of host blood vessels into clefts formed by degeneration of graft tissue. For a period, a hemostasis occurs in these blood-filled lacunae, and then endothel invasion from host vessels forms the proper wall. The transplant vasculature develops from these large sinusoids. The results challenge the role of the pre-existing donor vessels in transplant vascularization. A possible explanation of such paradoxical results is that the donor tissue must reach a stage of maturation to receive the ingrowing vessels, either host vessels, and the presence of vessels in the donor brain is the sign of this stage of maturation but has no direct role in transplant vascularization

Renal glutaminase adaptation and ammonia excretion in infant rats

1975 ◽  
Vol 228 (3) ◽  
pp. 693-698 ◽  
Author(s):  
S Benyajati ◽  
L Goldstein
Keyword(s):  
Actinomycin D ◽  
Ammonia Excretion ◽  
Repeated Administration ◽  
Adult Rats ◽  
Direct Role ◽  
Adult Level ◽  
Infant Rats ◽  
Treatment Administration ◽  
Enzyme Adaptation

The purpose of this investigation was to determine the role of enzyme adaptation in the response of ammonia excretion to acidosis in developing rats. The response of renal ammonia excretion was low in infant rats (7-12 days old) following administration of a single dose of acidifying salt (5 mmol NH4CL/kg). However, repeated administration (2 times daily) of the salt increased ammonia excretion two- to threefold within 2 days. This adaptive response was associated with a concomitant rise in renal phosphate-dependent glutaminase (PDG) activity; PDG activity increased from approximately 36% adult level in untreated infants to 79% adult level in infants given NH4Cl for 2 days. Ammonia excretion and PDG activity decreased in parallel following cessation of NH4Cl treatment. Administration of the antibiotic, actinomycin D (100 mug/kg, ip, 2 times daily for 2 days) completely inhibited the response of PDG to repeated NH4Cl administration. In contrast to the situation previously observed in adult rats, actinomycin D treatment prevented the acid-induced rise in renal ammonia excretion. These results suggest that the level of renal PDG plays a more direct role in the adaptation of ammonia excretion to acidosis in infant rats than in adults.

scholarly journals Skeletal defects in VEGF120/120 mice reveal multiple roles for VEGF in skeletogenesis

Development ◽  
2002 ◽  
Vol 129 (8) ◽  
pp. 1893-1904 ◽  
Author(s):  
Elazar Zelzer ◽  
William McLean ◽  
Yin-Shan Ng ◽  
Naomi Fukai ◽  
Anthony M. Reginato ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Skeletal Development ◽  
Surrounding Tissue ◽  
Ossification Center ◽  
Direct Role ◽  
Osteoblastic Activity ◽  
Chondrocyte Maturation ◽  
Skeletal Defects

Angiogenesis is an essential component of skeletal development and VEGF signaling plays an important if not pivotal role in this process. Previous attempts to examine the roles of VEGF in vivo have been largely unsuccessful because deletion of even one VEGF allele leads to embryonic lethality before skeletal development is initiated. The availability of mice expressing only the VEGF120 isoform (which do survive to term) has offered an opportunity to explore the function of VEGF during embryonic skeletal development. Our study of these mice provides new in vivo evidence for multiple important roles of VEGF in both endochondral and intramembranous bone formation, as well as some insights into isoform-specific functions. There are two key differences in vascularization of developing bones between wild-type and VEGF120/120 mice. VEGF120/120 mice have not only a delayed recruitment of blood vessels into the perichondrium but also show delayed invasion of vessels into the primary ossification center, demonstrating a significant role of VEGF at both an early and late stage of cartilage vascularization. These findings are the basis for a two-step model of VEGF-controlled vascularization of the developing skeleton, a hypothesis that is supported by the new finding that VEGF is expressed robustly in the perichondrium and surrounding tissue of cartilage templates of future bones well before blood vessels appear in these regions. We also describe new in vivo evidence for a possible role of VEGF in chondrocyte maturation, and document that VEGF has a direct role in regulating osteoblastic activity based on in vivo evidence and organ culture experiments.

Assessing the size of agricultural holdings

2020 ◽  
pp. 105-116
Author(s):  
N. I. Shagaida
Keyword(s):  
Russian Federation ◽  
Vertical Integration ◽  
Total Revenue ◽  
Large Share ◽  
State Support ◽  
The Russian Federation ◽  
Agricultural Organizations ◽  
Business Entities ◽  
To Receive

The article clarifies the concept of “agricultural holding”, using an approach to assessing the size on the basis of the total revenue of all agricultural organizations within the agricultural holding. It has been revealed that only 100 of the total number of agricultural holdings that were identified can be attributed to large business entities. They comprise about 3% of agricultural organizations in the country, while their share in the proceeds is about 37%. A large share of agricultural holdings — large business subjects under the control of Russian entities operate in one, and under the control of foreign legal entities — in three or more regions of the Russian Federation. Vertical integration within the framework of large agricultural holdings with different schemes for including the stages of processing and sale of products produced in their agricultural organizations allows them to receive advantages. Strengthening the role of large business entities in agriculture puts on the agenda the issue of differentiating approaches to taxation and state support in agriculture, depending on the size of the companies’ agricultural businesses.

Provision of Remedies for Violation of Economic, Social and Cultural Rights: A Comparative Study of the United Nations, Inter-American and African Human Rights Systems

2020 ◽  
Vol 28 (2) ◽  
pp. 298-318
Author(s):  
Roman Girma Teshome
Keyword(s):  
Human Rights ◽  
United Nations ◽  
Comparative Study ◽  
Economic Rights ◽  
Regional Monitoring ◽  
Cultural Rights ◽  
The Past ◽  
The United Nations ◽  
To Receive

The effectiveness of human rights adjudicative procedures partly, if not most importantly, hinges upon the adequacy of the remedies they grant and the implementation of those remedies. This assertion also holds water with regard to the international and regional monitoring bodies established to receive individual complaints related to economic, social and cultural rights (hereinafter ‘ESC rights’ or ‘socio-economic rights’). Remedies can serve two major functions: they are meant, first, to rectify the pecuniary and non-pecuniary damage sustained by the particular victim, and second, to resolve systematic problems existing in the state machinery in order to ensure the non-repetition of the act. Hence, the role of remedies is not confined to correcting the past but also shaping the future by providing reforming measures a state has to undertake. The adequacy of remedies awarded by international and regional human rights bodies is also assessed based on these two benchmarks. The present article examines these issues in relation to individual complaint procedures that deal with the violation of ESC rights, with particular reference to the case laws of the three jurisdictions selected for this work, i.e. the United Nations, Inter-American and African Human Rights Systems.

THE ROLE OF DIFFERENT WAYS OF NITRITE OXIDE GENERATION IN MAMMALIAN BLOOD VESSELS IN AGING

Tsitologiya ◽  
2018 ◽  
Vol 60 (1) ◽  
pp. 5-13 ◽  
Author(s):  
N. V. Kuleva ◽  
◽  
D. A. Fedorov ◽  
I. E. Krasovskaya ◽  
◽  
...  
Keyword(s):  
Blood Vessels ◽  
Nitrite Oxide ◽  
Mammalian Blood

Shifting Roles in Continuous Advising Sessions

Relay Journal ◽  
2019 ◽  
pp. 69-72
Author(s):  
Huw Davies ◽  
Robert Stevenson ◽  
Isra Wongsarnpigoon
Keyword(s):  
Learning Process ◽  
Transformational Learning ◽  
Learning Trajectory ◽  
Learner Readiness ◽  
Linguistic Support ◽  
Reflective Dialogue ◽  
Open Mind ◽  
To Receive

It is common for learning advisors to receive a request such as conversation practice or simple linguistic support in our institution simply because learners find them accessible and friendly. Although this may not be the usual role of a learning advisor, it can be the beginning of a long-lasting reflective dialogue. Learning advisors are aware that the learners’ initial interest is not necessarily an opportunity for reflection on their learning process. Nevertheless, they also acknowledge the fact that learner readiness for reflection varies depending on the learner. Thus, while advisors appear to be “conversation partners” at first, they endeavor to create reflective dialogues by incorporating advising strategies in each session. As the learning trajectory that the learner follows is not always straightforward, keeping an open mind and engaging in each advising session is crucial. The following stories depict the importance of openness to learners’ needs and maintaining continuous advising sessions in order to generate transformational learning.

Bioengineered in vitro Vascular Models for Applications in Interventional Radiology

2019 ◽  
Vol 24 (45) ◽  
pp. 5367-5374 ◽  
Author(s):  
Xiaoyun Li ◽  
Seyed M. Moosavi-Basri ◽  
Rahul Sheth ◽  
Xiaoying Wang ◽  
Yu S. Zhang
Keyword(s):  
Interventional Radiology ◽  
Animal Models ◽  
Blood Vessels ◽  
In Vitro Models ◽  
The Past ◽  
Endovascular Interventions ◽  
Conventional Animal ◽  
Vascular Structures

The role of endovascular interventions has progressed rapidly over the past several decades. While animal models have long-served as the mainstay for the advancement of this field, the use of in vitro models has become increasingly widely adopted with recent advances in engineering technologies. Here, we review the strategies, mainly including bioprinting and microfabrication, which allow for fabrication of biomimetic vascular models that will potentially serve to supplement the conventional animal models for convenient investigations of endovascular interventions. Besides normal blood vessels, those in diseased states, such as thrombosis, may also be modeled by integrating cues that simulate the microenvironment of vascular disorders. These novel engineering strategies for the development of biomimetic in vitro vascular structures will possibly enable unconventional means of studying complex endovascular intervention problems that are otherwise hard to address using existing models.

Injecting Knowledge

2017 ◽  
Author(s):  
Lucia Dacome
Keyword(s):  
Eighteenth Century ◽  
Blood Vessels ◽  
Comparative Perspective ◽  
Anatomical Models ◽  
Early Stages ◽  
The Creation ◽  
Cabinet Of Curiosities

Chapter 7 furthers the analysis of the role of anatomical models as cultural currencies capable of transferring value. It does so by expanding the investigation of the early stages of anatomical modelling to include a new setting. In particular, it follows the journey of the Palermitan anatomist and modeller Giuseppe Salerno and his anatomical ‘skeleton’—a specimen that represented the body’s complex web of blood vessels and was presented as the result of anatomical injections. Although Salerno was headed towards Bologna, a major centre of anatomical modelling, he ended his journey in Naples after the nobleman Raimondo di Sangro purchased the skeleton for his own cabinet of curiosities. This chapter considers the creation and viewing of an anatomical display in di Sangro’s Neapolitan Palace from a comparative perspective that highlights how geography and locality played an important part in shaping the culture of mid-eighteenth-century anatomical modelling.

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