scholarly journals Kisspeptin Neurons from Mice to Men: Similarities and Differences

Endocrinology ◽  
2012 ◽  
Vol 153 (11) ◽  
pp. 5105-5118 ◽  
Author(s):  
Robert L. Goodman ◽  
Michael N. Lehman
Keyword(s):  
Strong Evidence ◽  
Species Differences ◽  
Mammalian Species ◽  
Limited Area ◽  
Sexually Dimorphic ◽  
Functional Consequences ◽  
Similarities And Differences ◽  
Reproductive Neuroendocrinology ◽  
Two Populations

Abstract The discovery that kisspeptin was critical for normal fertility in humans ushered in a new chapter in our understanding of the control of GnRH secretion. In this paper, we will review recent data on the similarities and differences across several mammalian species in the role of kisspeptin in reproductive neuroendocrinology. In all mammals examined to date, there is strong evidence that kisspeptin plays a key role in the onset of puberty and is necessary for both tonic and surge secretion of GnRH in adults, although kisspeptin-independent systems are also apparent in these studies. Similarly, two groups of kisspeptin neurons, one in the arcuate nucleus (ARC) and the other more rostrally, have been identified in all mammals, although the latter is concentrated in a limited area in rodents and more scattered in other species. Estrogen has divergent actions on kisspeptin expression in these two regions across these species, stimulating it the latter and inhibiting expression in the former. There is also strong evidence that the rostral population participates in the GnRH surge, whereas the ARC population contributes to steroid-negative feedback. There may be species differences in the role of these two populations in puberty, with the ARC cells important in rats, sheep, and monkeys, whereas both have been implicated in mice. ARC kisspeptin neurons also appear to participate in the GnRH surge in sheep and guinea pigs, whereas the data on this possibility in rodents are contradictory. Similarly, both populations are sexually dimorphic in sheep and humans, whereas most data in rodents indicate that this occurs only in the rostral population. The functional consequences of these species differences remain to be fully elucidated but are likely to have significance for understanding normal neuroendocrine control of reproduction as well as for use of kisspeptin agonists/antagonists as a therapeutic tool.

Antithrombin Dublin (p.Val30Glu): a relatively common variant with moderate thrombosis risk of causing transient antithrombin deficiency

2016 ◽  
Vol 116 (07) ◽  
pp. 146-154 ◽  
Author(s):  
José Navarro-Fernández ◽  
María Morena-Barrio ◽  
José Padilla ◽  
Antonia Miñano ◽  
Nataliya Bohdan ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Thrombotic Event ◽  
Type I ◽  
Antithrombin Deficiency ◽  
Amino Terminal ◽  
Thrombosis Risk ◽  
Functional Consequences ◽  
Low Incidence ◽  
Two Populations

SummaryThe key haemostatic role of antithrombin and the risk of thrombosis associated with its deficiency support that the low incidence of antithrombin deficiency among patients with thrombosis might be explained by underestimation of this disorder. It was our aim to identify mutations in SERPINC1 causing transient antithrombin deficiency. SERPINC1 was sequenced in 214 cases with a positive test for antithrombin deficiency, including 67 with no deficiency in the sample delivered to our laboratory. The p.Val30Glu mutation (Antithrombin Dublin) was identified in five out of these 67 cases, as well as in three out of 127 cases with other SERPINC1 mutations. Genotyping in 1593 patients with venous thrombosis and 2592 controls from two populations, revealed a low prevalent polymorphism (0.3 %) that moderately increased the risk of venous thrombosis (OR: 2.9; 95 % CI: 1.07–8.09; p= 0.03) and identified one homozygous patient with an early thrombotic event. Carriers had normal anti-FXa activity, and plasma antithrombin was not sensitive to heat stress or proteolytic cleavage. Analysis of one sample with transient deficit revealed a type I deficiency, without aberrant or increased latent forms. The recombinant variant, which lacked the two amino-terminal residues, had reduced secretion from HEK-EBNA cells, formed hyperstable disulphidelinked polymers, and had negligible activity. In conclusion, p.Val30Glu by affecting the cleavage of antithrombin’s signal peptide, results in a mature protein lacking the N-terminal dipeptide with no functional consequences in normal conditions, but that increases the sensitivity to be folded intracellularly into polymers, facilitating transient antithrombin deficiency and the subsequent risk of thrombosis.

The Use of Liver Cell Cultures Derived from Different Mammalian Species in In Vitro Toxicological Studies: Implementation in Extrapolation Models?

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 251-258 ◽  
Author(s):  
Bas J. Blaauboer ◽  
Heleen M. Wortelboer ◽  
Wim C. Mennes
Keyword(s):  
Species Differences ◽  
Mammalian Species ◽  
Cell Types ◽  
In Vitro Techniques ◽  
Toxicological Studies ◽  
In Vitro Systems ◽  
Underlying Mechanisms ◽  
Insight Into

In vitro techniques can be applied to obtain insight into the organotoxic potential of compounds and in the underlying mechanisms of action. During the last few decades the applicability of these techniques in toxicology has been demonstrated for an increasing number of cell types. Cultured hepatocytes have been shown to provide convenient in vitro systems for studying the role of biotransformation in the toxicity of a compound. The use of in vitro systems derived from a range of species may lead to a better understanding of species differences in the toxicity of xenobiotics, thus improving interspecies extrapolations. The applicability of this approach will be illustrated with results from experiments on the biotransformation and cytotoxicity of bromobenzene, the in vitro inducibility of biotransformation enzyme systems and the effects of hypolipidemics in primary hepatocyte cultures derived from a numberof animals.

Concurrent Electrodermal and Eyeblink Conditioning With Masked and Unmasked Stimuli

2021 ◽  
Vol 35 (1) ◽  
pp. 35-42
Author(s):  
José Luis Marcos ◽  
Azahara Marcos
Keyword(s):  
Unconditioned Stimulus ◽  
Strong Evidence ◽  
Eyeblink Conditioning ◽  
Noise Burst ◽  
Conditioning Phase ◽  
Contingency Awareness ◽  
Blank Screen ◽  
Neutral Face ◽  
Fearful Face

Abstract. The aim of this study was to determine if contingency awareness between the conditioned (CS) and unconditioned stimulus (US) is necessary for concurrent electrodermal and eyeblink conditioning to masked stimuli. An angry woman’s face (CS+) and a fearful face (CS−) were presented for 23 milliseconds (ms) and followed by a neutral face as a mask. A 98 dB noise burst (US) was administered 477 ms after CS+ offset to elicit both electrodermal and eyeblink responses. For the unmasking conditioning a 176 ms blank screen was inserted between the CS and the mask. Contingency awareness was assessed using trial-by-trial ratings of US-expectancy in a post-conditioning phase. The results showed acquisition of differential electrodermal and eyeblink conditioning in aware, but not in unaware participants. Acquisition of differential eyeblink conditioning required more trials than electrodermal conditioning. These results provided strong evidence of the causal role of contingency awareness on differential eyeblink and electrodermal conditioning.

BLOCKADE OF THE SURGE OF PROLACTIN AT PRO-OESTRUS BY ADMINISTRATION OF ANTI-OESTROGENIC SUBSTANCE, MER-25

1973 ◽  
Vol 74 (4) ◽  
pp. 769-774 ◽  
Author(s):  
Akira Yokoyama ◽  
Hiroshi Tomogane ◽  
Katuaki Ôta
Keyword(s):  
Strong Evidence ◽  
The Other ◽  
Other Hand

ABSTRACT A non-steroidal oestrogen antagonist, MER-25, was administered to cycling rats for elucidating the role of oestrogen in the surge of prolactin observed on the afternoon of pro-oestrus (POe). In animals injected with 20 mg of MER-25 intramuscularly on the afternoon (16.30 h) of the first day of dioestrus (D-1), the surge of prolactin was blocked while the level of prolactin on the afternoon of POe of these animals was significantly higher than that of the corresponding controls injected with oil. Ovulation was also blocked in these animals treated with the drug on the afternoon of D-l. On the other hand, treatment on the morning (10.30 h) of the 2nd day of dioestrus failed to prevent not only the surge of prolactin but also ovulation. These observations provide strong evidence for the view that oestrogen is responsible for the surge of prolactin on the afternoon of POe, and that the surge is accompanied by that of LH.

The role of Constitutional Courts in Transitional Justice: Colombia and South Africa

2016 ◽  
Vol 9 (15) ◽  
Author(s):  
Nadiehezka Paola Palencia Tejedor
Keyword(s):  
South Africa ◽  
Structural Analysis ◽  
Transitional Justice ◽  
Critical Analysis ◽  
Historical Context ◽  
Constitutional Courts ◽  
Political Background ◽  
Similarities And Differences ◽  
Peace And Reconciliation

This work focuses on a compared analysis of the South Afri- can decision related to the “peace and reconciliation act” of this country’s Parliament, and the Colombian decision regarding the amendment of the constitution called “The juridical framework for the peace.” Turning to the structure, it is developed in three major topics: 1. It provides a brief of the historical context, political background and an overview of the two decisions.2. It gives a structural analysis of the powers that each Court has and the nature of the constitutional mechanism through which both Courts decided the constitutionality of the said norms 3. It presents a critical analysis on the similarities and differences between the two systems and judgments. It presents some con- clusions. 

Composition and characteristics of the financial statements elements in accordance with IFRS

2020 ◽  
pp. 36-42
Author(s):  
Mohammad Tariq Jassim
Keyword(s):  
Financial Reporting ◽  
Financial Statements ◽  
International Financial Reporting Standards ◽  
International Accounting ◽  
Reporting Standards ◽  
Financial Reporting Standards ◽  
Current Trends ◽  
Similarities And Differences ◽  
Qualitative Characteristics

In a market economy, the role of International Financial Reporting Standards is increasing. In order to understand their significance in modern conditions it seems necessary to consider the peculiarities of evolution of IFRS formation. The article reflects actual issues concerning the role and significance of International Accounting and Reporting Standards in modern conditions. The author has defined the necessity of applying International Accounting and Reporting Standards by Russian companies. The article highlights the main elements and users of financial statements prepared on the basis of IFRS, and analyzes the similarities and differences that exist in the formation of financial statements, based on the requirements of IFRS and RAS. The main qualitative characteristics of financial statements are considered in detail. Based on the results of the research, the author has identified current trends in the transition to international financial reporting standards.

Comparison with an indeterminate pronoun

2017 ◽  
Author(s):  
Osamu Sawada
Keyword(s):  
Scale Structure ◽  
Dual Use ◽  
Discourse Context ◽  
Individual Comparison ◽  
Similarities And Differences ◽  
Striking Parallelism

Chapter 4 focuses on the dual-use phenomenon of comparison with an indeterminate pronoun in Japanese (and other languages) and considers the similarities and differences between at-issue comparative meaning (i.e. individual comparison) and a CI comparative meaning (i.e. noteworthy comparison). Although an individual comparison and a noteworthy comparison are compositionally and dimensionally different, there is a striking parallelism in terms of the scale structure. The chapter explains the similarities and differences between the two kinds of comparison in a systematic way. It also considers the role of scalarity and comparison in a discourse context and argues that they provide a way of signaling to what extent an at-issue utterance contributes to the goal of the conversation. The timing of signaling information on noteworthiness in a discourse and its pragmatic effect are also discussed.

scholarly journals Pannexins and Connexins: Their Relevance for Oocyte Developmental Competence

2021 ◽  
Vol 22 (11) ◽  
pp. 5918
Author(s):  
Paweł Kordowitzki ◽  
Gabriela Sokołowska ◽  
Marta Wasielak-Politowska ◽  
Agnieszka Skowronska ◽  
Mariusz T. Skowronski
Keyword(s):  
Assisted Reproductive Technologies ◽  
Mammalian Species ◽  
Atp Release ◽  
Reproductive Technologies ◽  
High Energy ◽  
Developmental Competence ◽  
Physiological Processes ◽  
Protein Group ◽  
Multicellular Organisms

The oocyte is the major determinant of embryo developmental competence in all mammalian species. Although fundamental advances have been generated in the field of reproductive medicine and assisted reproductive technologies in the past three decades, researchers and clinicians are still trying to elucidate molecular factors and pathways, which could be pivotal for the oocyte’s developmental competence. The cell-to-cell and cell-to-matrix communications are crucial not only for oocytes but also for multicellular organisms in general. This latter mentioned communication is among others possibly due to the Connexin and Pannexin families of large-pore forming channels. Pannexins belong to a protein group of ATP-release channels, therefore of high importance for the oocyte due to its requirements of high energy supply. An increasing body of studies on Pannexins provided evidence that these channels not only play a role during physiological processes of an oocyte but also during pathological circumstances which could lead to the development of diseases or infertility. Connexins are proteins that form membrane channels and gap-junctions, and more precisely, these proteins enable the exchange of some ions and molecules, and therefore they do play a fundamental role in the communication between the oocyte and accompanying cells. Herein, the role of Pannexins and Connexins for the processes of oogenesis, folliculogenesis, oocyte maturation and fertilization will be discussed and, at the end of this review, Pannexin and Connexin related pathologies and their impact on the developmental competence of oocytes will be provided.

scholarly journals Imaging Familial and Sporadic Neurodegenerative Disorders Associated with Parkinsonism

2021 ◽  
Author(s):  
David J. Brooks
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Disorders ◽  
Lewy Body Dementia ◽  
Imaging Biomarkers ◽  
Imaging Findings ◽  
Subclinical Disease ◽  
Similarities And Differences ◽  
Potential Use

AbstractIn this paper, the structural and functional imaging changes associated with sporadic and genetic Parkinson’s disease and atypical Parkinsonian variants are reviewed. The role of imaging for supporting diagnosis and detecting subclinical disease is discussed, and the potential use and drawbacks of using imaging biomarkers for monitoring disease progression is debated. Imaging changes associated with nonmotor complications of PD are presented. The similarities and differences in imaging findings in Lewy body dementia, Parkinson’s disease dementia, and Alzheimer’s disease are discussed.

scholarly journals Isoform-Specific Roles of Mutant p63 in Human Diseases

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 536
Author(s):  
Christian Osterburg ◽  
Susanne Osterburg ◽  
Huiqing Zhou ◽  
Caterina Missero ◽  
Volker Dötsch
Keyword(s):  
Cleft Lip ◽  
Ectodermal Dysplasia ◽  
Skin Development ◽  
Disease Mechanisms ◽  
Skin Fragility ◽  
Cleft Lip Palate ◽  
Life Threatening ◽  
Functional Consequences ◽  
Development And Differentiation

The p63 gene encodes a master regulator of epidermal commitment, development, and differentiation. Heterozygous mutations in the DNA binding domain cause Ectrodactyly, Ectodermal Dysplasia, characterized by limb deformation, cleft lip/palate, and ectodermal dysplasia while mutations in in the C-terminal domain of the α-isoform cause Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) syndrome, a life-threatening disorder characterized by skin fragility, severe, long-lasting skin erosions, and cleft lip/palate. The molecular disease mechanisms of these syndromes have recently become elucidated and have enhanced our understanding of the role of p63 in epidermal development. Here we review the molecular cause and functional consequences of these p63-mutations for skin development and discuss the consequences of p63 mutations for female fertility.

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