scholarly journals Pulsatility of Hypothalamo-Pituitary Hormones: A Challenge in Quantification

Physiology ◽  
2016 ◽  
Vol 31 (1) ◽  
pp. 34-50 ◽  
Author(s):  
Daniel M. Keenan ◽  
Johannes D. Veldhuis
Keyword(s):  
Present Article ◽  
Pituitary Hormones ◽  
Specific Target ◽  
Physiological Processes ◽  
Systems Control ◽  
Neuroendocrine Systems

Neuroendocrine systems control many of the most fundamental physiological processes, e.g., reproduction, growth, adaptations to stress, and metabolism. Each such system involves the hypothalamus, the pituitary, and a specific target gland or organ. In the quantification of the interactions among these components, biostatistical modeling has played an important role. In the present article, five key challenges to an understanding of the interactions of these systems are illustrated and discussed critically.

Referring to arbitrary entities with placeholders

Pragmatics ◽  
2021 ◽  
Author(s):  
Tohru Seraku
Keyword(s):  
Target Word ◽  
Present Article ◽  
Original Data ◽  
Specific Target ◽  
Action Event ◽  
Target Form ◽  
Referential Function

Abstract A speaker/writer uses a placeholder (PH) to fill in the syntactic slot of a target word when she has no immediate access to the word or prefers to avoid explicitly mentioning it for contextual reasons. In the present article, I point out a hitherto understudied usage of PHs: a speaker/writer who does not have in mind a specific target form may use a PH to refer to an arbitrary entity (e.g. person, object, action, event, proposition). I substantiate this claim by analysing a variety of original data on Japanese wh-derived PHs. Further evidence for this claim comes from a cross-linguistic survey of wh-derived PHs in Korean and demonstrative-derived PHs in Romanian and Bulgarian. I show that the arbitrary-referential function is observed in PHs in all these languages, regardless of their origins (i.e. wh word, demonstrative) and their categories (i.e. nominal, verbal).

The concept of Happiness in Ayurveda

2017 ◽  
Vol 2 (05) ◽  
Author(s):  
Shivaprasad Chiplunkar ◽  
Ravi KV. Bhat ◽  
Reshmi Pushpan ◽  
Chitra Mukul Gawande
Keyword(s):  
Present Article ◽  
Research Work ◽  
Healthy People ◽  
Important Place ◽  
Happy Life ◽  
Physiological Processes ◽  
Different Dimensions

The quest for happiness is something that has enthralled every human since time immemorial. Researchers belonging to different fields along with ancient spiritual scholars have strived to arrive at a pathway for happiness. But since happiness involves different dimensions of itself, the interpretations on happiness have also been varied and different. Ayurveda is a science that was designed to maintain the health of healthy people and to cure the maladies of the unhealthy people. Happiness is an important facet of health and hence is given an important place in Ayurveda. The Ancient Ayurvedic literature has explained the concept of happiness under various terminologies like Sukha, Harsha etc. In the present research work all the fundamental texts of Ayurveda were screened thoroughly in order to compile the information on concept of happiness in Ayurveda. This was used to draw various interpretations on the science of happiness. The present article is written in order to envisage this concept of happiness in Ayurveda. The article will try to throw light on the usefulness of happiness in health, role of happiness on Dosha, Dhatu Mala and other physiological processes. The article also aims to suggest ways to achieve happy life with the help of fundamental principles of Ayurveda.

scholarly journals Regulation of Pituitary Progenitor Differentiation by β-Catenin

Endocrinology ◽  
2018 ◽  
Vol 159 (9) ◽  
pp. 3287-3305 ◽  
Author(s):  
Julie L Youngblood ◽  
Tanner F Coleman ◽  
Shannon W Davis
Keyword(s):  
Critical Time ◽  
Cell Types ◽  
Pituitary Hormones ◽  
Pituitary Hormone ◽  
Specific Cell ◽  
Lineage Specification ◽  
Gain Of Function ◽  
Physiological Processes ◽  
Critical Organ ◽  
Time Point

Abstract The pituitary gland is a critical organ that is necessary for many physiological processes, including growth, reproduction, and stress response. The secretion of pituitary hormones from specific cell types regulates these essential processes. Pituitary hormone cell types arise from a common pool of pituitary progenitors, and mutations that disrupt the formation and differentiation of pituitary progenitors result in hypopituitarism. Canonical WNT signaling through CTNNB1 (β-catenin) is known to regulate the formation of the POU1F1 lineage of pituitary cell types. When β-catenin is deleted during the initial formation of the pituitary progenitors, Pou1f1 is not transcribed, which leads to the loss of the POU1F1 lineage. However, when β-catenin is deleted after lineage specification, there is no observable effect. Similarly, the generation of a β-catenin gain-of-function allele in early pituitary progenitors or stem cells results in the formation of craniopharyngiomas, whereas stimulating β-catenin in differentiated cell types has no effect. PROP1 is a pituitary-specific transcription factor, and the peak of PROP1 expression coincides with a critical time point in pituitary organogenesis—that is, after pituitary progenitor formation but before lineage specification. We used a Prop1-cre to conduct both loss- and gain-of-function studies on β-catenin during this critical time point. Our results demonstrate that pituitary progenitors remain sensitive to both loss and gain of β-catenin at this time point, and that either manipulation results in hypopituitarism.

scholarly journals Effects of Melatonin on Anterior Pituitary Plasticity: A Comparison Between Mammals and Teleosts

2021 ◽  
Vol 11 ◽  
Author(s):  
Elia Ciani ◽  
Trude M. Haug ◽  
Gersende Maugars ◽  
Finn-Arne Weltzien ◽  
Jack Falcón ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Pituitary Hormones ◽  
Future Research ◽  
Pituitary Hormone ◽  
Hormone Production ◽  
Physiological Processes ◽  
Important Target ◽  
Specific Receptors ◽  
Positive And Negative Feedback

Melatonin is a key hormone involved in the photoperiodic signaling pathway. In both teleosts and mammals, melatonin produced in the pineal gland at night is released into the blood and cerebrospinal fluid, providing rhythmic information to the whole organism. Melatonin acts via specific receptors, allowing the synchronization of daily and annual physiological rhythms to environmental conditions. The pituitary gland, which produces several hormones involved in a variety of physiological processes such as growth, metabolism, stress and reproduction, is an important target of melatonin. Melatonin modulates pituitary cellular activities, adjusting the synthesis and release of the different pituitary hormones to the functional demands, which changes during the day, seasons and life stages. It is, however, not always clear whether melatonin acts directly or indirectly on the pituitary. Indeed, melatonin also acts both upstream, on brain centers that control the pituitary hormone production and release, as well as downstream, on the tissues targeted by the pituitary hormones, which provide positive and negative feedback to the pituitary gland. In this review, we describe the known pathways through which melatonin modulates anterior pituitary hormonal production, distinguishing indirect effects mediated by brain centers from direct effects on the anterior pituitary. We also highlight similarities and differences between teleosts and mammals, drawing attention to knowledge gaps, and suggesting aims for future research.

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

Ultrastructural morphology of nontumorous lactotrophs in human pituitaries exposed to high prolactin levels

1987 ◽  
Vol 45 ◽  
pp. 896-897
Author(s):  
S. Jalalah ◽  
K. Kovacs ◽  
E. Horvath
Keyword(s):  
Anterior Pituitary ◽  
Secretory Activity ◽  
Pituitary Hormones ◽  
Feedback Mechanism ◽  
Endocrine Activity ◽  
Hormone Synthesis ◽  
Anterior Pituitary Hormones ◽  
Negative Feedback Mechanism ◽  
Ultrastructural Morphology ◽  
Transmission Electron

Lactotrophs, as many other endocrine cells, change their morphology in response to factors influencing their secretory activity. Secretion of prolactin (PRL) from lactotrophs, like that of other anterior pituitary hormones, is under the control of the hypothalamus. Unlike most anterior pituitary hormones, PRL has no apparent target gland which could modulate the endocrine activity of lactotrophs. It is generally agreed that PRL regulates its own release from lactotrophs via the short loop negative feedback mechanism exerted at the level of the hypothalamus or the pituitary. Accordingly, ultrastructural morphology of lactotrophs is not constant; it is changing in response to high PRL levels showing signs of suppressed hormone synthesis and secretion.By transmission electron microscopy and morphometry, we have studied the morphology of lactotrophs in nontumorous (NT) portions of 7 human pituitaries containing PRL-secreting adenoma; these lactotrophs were exposed to abnormally high PRL levels.

A Scanning Electron Microscopic Study of Pro-Vascular Cellular Morphology in Chaetophora Incressata

1985 ◽  
Vol 43 ◽  
pp. 638-639
Author(s):  
A. E. Hotchkiss ◽  
A. T. Hotchkiss ◽  
R. P. Apkarian
Keyword(s):  
Green Algae ◽  
Vascular Plants ◽  
Vascular System ◽  
Higher Plants ◽  
Wall Structure ◽  
Electron Microscopic ◽  
Physiological Processes ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Multicellular green algae may be an ancestral form of the vascular plants. These algae exhibit cell wall structure, chlorophyll pigmentation, and physiological processes similar to those of higher plants. The presence of a vascular system which provides water, minerals, and nutrients to remote tissues in higher plants was believed unnecessary for the algae. Among the green algae, the Chaetophorales are complex highly branched forms that might require some means of nutrient transport. The Chaetophorales do possess apical meristematic groups of cells that have growth orientations suggestive of stem and root positions. Branches of Chaetophora incressata were examined by the scanning electron microscope (SEM) for ultrastructural evidence of pro-vascular transport.

The German Post-Critical Belief Scale: Internal and External Validity

2003 ◽  
Vol 34 (4) ◽  
pp. 219-226 ◽  
Author(s):  
Bart Duriez ◽  
Claudia Appel ◽  
Dirk Hutsebaut
Keyword(s):  
Internal Structure ◽  
Present Article ◽  
External Validity ◽  
German Version ◽  
Dutch Version ◽  
German Sample ◽  
Belief Scale ◽  
Internal And External Validity

Abstract: Recently, Duriez, Fontaine and Hutsebaut (2000) and Fontaine, Duriez, Luyten and Hutsebaut (2003) constructed the Post-Critical Belief Scale in order to measure the two religiosity dimensions along which Wulff (1991 , 1997 ) summarized the various possible approaches to religion: Exclusion vs. Inclusion of Transcendence and Literal vs. Symbolic. In the present article, the German version of this scale is presented. Results obtained in a heterogeneous German sample (N = 216) suggest that the internal structure of the German version fits the internal structure of the original Dutch version. Moreover, the observed relation between the Literal vs. Symbolic dimension and racism, which was in line with previous studies ( Duriez, in press ), supports the external validity of the German version.

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