scholarly journals An Original Method for Removing and Fixing the Pituitary Gland of Sexually Mature Rats for Creating High-Quality Permanent Histological Preparations

2021 ◽  
Vol 6 (1) ◽  
pp. 303-310
Author(s):  
N. B. Hryntsova ◽  
◽  
A. M. Romanyuk
Keyword(s):  
Pituitary Gland ◽  
Experimental Studies ◽  
Original Method ◽  
Sphenoid Bone ◽  
Experimental Medicine ◽  
Endocrine Gland ◽  
Endocrine Regulation ◽  
High Quality ◽  
Pituitary Fossa ◽  
Sexually Mature

The issue of high-quality creating histological preparations is an urgent issue of histology and pathological anatomy, experimental medicine and biology. The pituitary gland belongs to the smallest in mass and size of the endocrine glands in both humans and animals, it is an endocrine gland and occupies one of the central places in the endocrine regulation of the body's vital activity. The study of the features of the removal of the pituitary gland from Turkish saddle of the sphenoid bone of the skull of rats remains an important aspect of modern morphology. The purpose of the work was to develop an original technique for improving the first (removal) and second (material fixation) stages of creating histological preparations of the rat pituitary gland for morphological, morphometric, and immunohistochemical medico-biological experimental studies. Material and methods. The development of the methodology was carried out on 200 white sexually mature rats of different sex weighing 250-300 g at the age of 7-8 months in accordance with the National and European bioethical standards. Results and discussion. Modification of the technique of extracting the pituitary gland of rats includes the introduction of the animal into thiopental anesthesia, decapitation, separation of the skin and muscular integument of the head, resection of the occipital bone of the skull, exposure and removal of the brain, identification of the pituitary gland, followed by removal of the pituitary gland with a single complex (block) together with the pituitary fossa Turkish saddle and fragments of the sphenoid bone adjacent to it. The gland was fixed with a reduced concentration of a 5% solution of buffered neutral formalin. After 15-18 hours from the beginning of fixation, the complex was temporarily removed from the fixator, and the pituitary gland was removed from the pituitary fossa of Turkish saddle using eye scalpel and eye forceps. The organ had a well-fixed and compacted capsule, which prevented unnecessary trauma and fragmentation of the organ during removal. The removed pituitary gland was again immersed in a 5% solution of neutral buffered formalin for 2-3 hours. After the end of the fixation period, the pituitary gland had a well-fixed structure and was subject to the following standard stages of making permanent histological specimens

scholarly journals THE VARIABILITY AND THE RATIO OF THE PITUITARY GLAND AND PITUITARY FOSSA LINEAR PARAMETERS DEPENDING ON THE SKULL BASE ANGLE

2021 ◽  
Vol 11 (4) ◽  
pp. 55-59
Author(s):  
Olga Aleshkina ◽  
Tatiana Bikbaeva ◽  
Anton Devyatkin ◽  
Marina Markeeva ◽  
Tatyana Zagorovskaya ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Pituitary Gland ◽  
Skull Base ◽  
Volume Ratio ◽  
Morphometric Parameters ◽  
Sphenoid Bone ◽  
Pituitary Fossa ◽  
Bending Angle ◽  
Base Angle

Details of the morpho- & topometric variability of the skull elements and soft tissue formations in the area of the sphenoid bone body, as well as their relationship, serve as the basis for the choice of proper surgical accesses to the respective area. The aim of this study was to identify the typical variability of morphometric parameters and the volume ratio between the pituitary gland and the Turkish saddle pituitary fossa in mature age adults. The method of computer craniometry (involving 100 MRI of people of the first and second periods of their mature age, 22–60) was employed to study the typical variability of the pituitary fossa and pituitary gland linear parameters, regardless of gender. The obtained data revealed that the regularity of morphometric variability and the volume ratio of the pituitary gland and the pituitary fossa depend on the skull base bending angle.

The Medial Wall of the Cavernous Sinus: Microsurgical Anatomy

Neurosurgery ◽  
2004 ◽  
Vol 55 (1) ◽  
pp. 179-190 ◽  
Author(s):  
Alexandre Yasuda ◽  
Alvaro Campero ◽  
Carolina Martins ◽  
Albert L. Rhoton ◽  
Guilherme C. Ribas
Keyword(s):  
Pituitary Gland ◽  
Cavernous Sinus ◽  
Thin Sheet ◽  
Single Layer ◽  
Lateral Wall ◽  
The Body ◽  
Medial Wall ◽  
Microsurgical Anatomy ◽  
Pituitary Fossa ◽  
Adjacent Structures

Abstract OBJECTIVE: This study was conducted to clarify the boundaries, relationships, and components of the medial wall of the cavernous sinus (CS). METHODS: Forty CSs, examined under ×3 to ×40 magnification, were dissected from lateral to medial in a stepwise fashion to expose the medial wall. Four CSs were dissected starting from the midline to lateral. RESULTS: The medial wall of the CS has two parts: sellar and sphenoidal. The sellar part is a thin sheet that separates the pituitary fossa from the venous spaces in the CS. This part, although thin, provided a barrier without perforations or defects in all cadaveric specimens studied. The sphenoidal part is formed by the dura lining the carotid sulcus on the body of the sphenoid bone. In all of the cadaveric specimens, the medial wall seemed to be formed by a single layer of dura that could not be separated easily into two layers as could the lateral wall. The intracavernous carotid was determined to be in direct contact with the pituitary gland, being separated from it by only the thin sellar part of the medial wall in 52.5% of cases. In 39 of 40 CSs, the venous plexus and spaces in the CS extended into the narrow space between the intracavernous carotid and the dura lining the carotid sulcus, which forms the sphenoidal part of the medial wall. The lateral surface of the pituitary gland was divided axially into superior, middle and inferior thirds. The intracavernous carotid coursed lateral to some part of all the superior, middle, and inferior thirds in 27.5% of the CSs, along the inferior and middle thirds in 32.5%, along only the inferior third in 35%, and below the level of the gland and sellar floor in 5%. In 18 of the 40 CSs, the pituitary gland displaced the sellar part of the medial wall laterally and rested against the intracavernous carotid, and in 6 there was a tongue-like lateral protrusion of the gland that extended around a portion of the wall of the intracavernous carotid. No defects were observed in the sellar part of the medial wall, even in the presence of these protrusions. CONCLUSION: The CS has an identifiable medial wall that separates the CS from the sella and capsule of the pituitary gland. The medial wall has two segments, sellar and sphenoidal, and is formed by just one layer of dura that cannot be separated into two layers as can the lateral wall of the CS. In this study, the relationships between the medial wall and adjacent structures demonstrated a marked variability.

Method of experimental evaluation of the efficiency coefficient of vibration protection of the rope-rod coupling "MAMSAR+A" of the diesel generator set DGA-8.83

2021 ◽  
pp. 88-95
Author(s):  
М.А. Минасян ◽  
А.М. Минасян ◽  
Ц. Цзэн
Keyword(s):  
Experimental Evaluation ◽  
Vibration Isolation ◽  
Experimental Studies ◽  
Original Method ◽  
Efficiency Coefficient ◽  
Diesel Generator ◽  
Vibration Protection ◽  
Rigid Connection ◽  
Two Stages

Объектом исследования является опытный образец запатентованной канатностержневой муфты (КСМ) «MAMSAR+А» в качестве привода дизель-генераторного агрегата ДГА-8,83 мощностью 9,56 кВт при частоте вращения 1500 мин-1 с дизелем 2Ч 8,5/11 и генератором «ГК-5,6». Целью исследования является экспериментальная оценка коэффициента эффективности вибрационной защиты КСМ. Поставленная цель достигается разработкой и реализацией оригинальной методики экспериментальной оценки коэффициента эффективности КСМ с анализом и выводами результатов экспериментальных исследований. Экспериментальные исследования проводятся в два этапа. Первый этап – с упругим соединением КСМ, второй этап – с жестким соединением. Оригинальность методики экспериментальной оценки коэффициента эффективности вибрационной защиты КСМ главным образом заключается в том, что между двумя этапами экспериментальных исследований КСМ не демонтируется. Следовательно, качество центровки не нарушается. Усредненный коэффициент эффективности виброизоляции КСМ составляет от 3 до 8 дБ. The object of this research is a prototype of the patented wire rope coupling (KSM) "MAMSAR+A" as a drive for a diesel-generator unit DGA-8.83 with a power of 9.56 kW at a speed of 1500 min-1 with a 2CH 8.5/11 diesel engine and a generator "KG-5.6". The aim of the research is to experimentally evaluate the efficiency coefficient of vibration protection of the KSM. This goal is achieved by developing and implementing an original method for experimental evaluation the efficiency coefficient of the KSM with analysis and conclusions of the results of experimental studies. Experimental studies are conducted in two stages. The first stage - with an elastic connection of the coupling, the second stage - with a rigid connection. The originality of the method of experimental evaluation of the efficiency coefficient of vibration protection of the KSM mainly lies in the fact that the KSM is not dismantled between the two stages of experimental research. Therefore, the quality of alignment is not violated. The average coefficient of vibration isolation efficiency of the KSM is from 3 to 8 dB.

scholarly journals Pituitary gland and growth hormone

2020 ◽  
pp. S109-S112
Author(s):  
MMA Mashinini
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Postnatal Growth ◽  
Endocrine Gland ◽  
Fetal Life ◽  
Endocrine Glands ◽  
Basic Aspect ◽  
Peripheral Action ◽  
Indirect Action ◽  
Somatotrophic Axis

The pituitary gland (PG) is said to be a “master” endocrine gland and through its tropic hormones influences other endocrine glands to secrete hormones that have a variety of effects on body systems. Growth hormone (GH) is a pituitary gland hormone that has direct and indirect effects produced by somatotrophs in early fetal life. It is essential for normal postnatal growth and has diverse effects across multiple physiological systems. The somatotrophic axis is made predominantly of GH, insulin-like growth factor 1 (IGF-1) and other factors regulating growth. This review summarises the relevant anatomical relationships of the PG, the basic aspect of GH physiology which includes mechanism of action (MOA), regulation and secretion and a direct and indirect action of GH through IGF-1, an important mediator of most of the peripheral action of GH.

scholarly journals The Pituitary Gland is a Novel Major Site of Action of Metformin in Non-Human Primates: a Potential Path to Expand and Integrate Its Metabolic Actions

2018 ◽  
Vol 49 (4) ◽  
pp. 1444-1459 ◽  
Author(s):  
Mari C. Vázquez-Borrego ◽  
Antonio C. Fuentes-Fayos ◽  
Manuel D. Gahete ◽  
Justo P. Castaño ◽  
Rhonda D. Kineman ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Signaling Pathways ◽  
Pituitary Hormones ◽  
Pituitary Cell ◽  
Metabolic Effects ◽  
Primate Species ◽  
Whole Body ◽  
Endocrine Gland ◽  
Papio Anubis ◽  
Human Primate

Background/Aims: Biguanides are anti-hyperglycaemic agents used to treat diabetes by acting primarily on the liver, inhibiting hepatic gluconeogenesis. However, biguanides may target other key metabolic tissues to exert beneficial actions. As the “master endocrine gland”, the pituitary is a true homeostatic sensor that controls whole body homeostasis and metabolism by integrating central and peripheral signals. However, whether the pituitary is a primary site of biguanides action in normal adult humans/primates remains unknown. Therefore, we aimed to elucidate the direct effects of two biguanides (metformin/phenformin) on the expression and secretion of all anterior pituitary hormones in two non-human primate species (Papio anubis and Macaca fascicularis), and the molecular/signalling-mechanisms behind these actions. Methods: Primary pituitary cell cultures from baboons and macaques were used to determine the direct impact of metformin/phenformin (alone and combined with primary regulators) on the functioning of all pituitary cell-types (i.e. expression/secretion/signaling-pathways, etc). Results: Metformin/phenformin inhibited basal, but not GHRH/ghrelin-stimulated GH/ACTH/ FSH-secretion and GH/POMC-expression, without altering secretion or expression of other pituitary hormones (PRL/LH/TSH), FSH-expression or cell viability in both primate models. These biguanide actions are likely mediated through modulation of: 1) common (mTOR/PI3K/intracellular-Ca2+mobilization) and distinct (MAPK) signaling pathways; and 2) gene expression of key receptors regulating somatotrope/corticotrope/gonadotrope function (i.e. upregulation of SSTR2/SSTR5/INSR/IGF1R/LEPR). Conclusion: The pituitary gland is a primary target of biguanide actions wherein they modulate somatotrope/corticotrope/gonadotrope-function through multiple molecular/signaling pathways in non-human primate-models. This suggests that the well-known metabolic effects of biguanides might be, at least in part, influenced by their actions at the pituitary level.

scholarly journals Interacting stressors matter: diet quality and virus infection in honeybee health

2019 ◽  
Vol 6 (2) ◽  
pp. 181803 ◽  
Author(s):  
Adam G. Dolezal ◽  
Jimena Carrillo-Tripp ◽  
Timothy M. Judd ◽  
W. Allen Miller ◽  
Bryony C. Bonning ◽  
...  
Keyword(s):  
Virus Infection ◽  
Multiple Stressors ◽  
Experimental Studies ◽  
Calcium Content ◽  
Micronutrient Deficiencies ◽  
Population Declines ◽  
High Quality ◽  
Diet Diversity ◽  
Extreme Stress ◽  
High Virus

Honeybee population declines have been linked to multiple stressors, including reduced diet diversity and increased exposure to understudied viral pathogens. Despite interest in these factors, few experimental studies have explored the interaction between diet diversity and viral infection in honeybees. Here, we used a mixture of laboratory cage and small semi-field nucleus hive experiments to determine how these factors interact. In laboratory experiments, we found that high-quality diets (polyfloral pollen and high-quality single-source pollen) have the potential to reduce mortality in the face of infection with Israeli acute paralysis virus (IAPV). There was a significant interaction between diet and virus infection on mortality, even in the presence of high virus titres, suggesting that good diets can help bees tolerate virus infection. Further, we found that extreme stress in the form of pollen starvation in conjunction with IAPV infection increase exiting behaviour from small experimental hives. Finally, we showed that higher-quality pollen diets have significantly higher iron and calcium content, suggesting micronutrient deficiencies could be an under-explored area of bee nutrition.

Analysis of Extrusion Welding Conditions for AlMg Alloys with High Mg Content

2016 ◽  
Vol 682 ◽  
pp. 401-407 ◽  
Author(s):  
Alicja Wojtyna ◽  
Dariusz Leśniak ◽  
Artur Rękas ◽  
Tomasz Latos ◽  
Krzysztof Zaborowski ◽  
...  
Keyword(s):  
Aluminium Alloys ◽  
Original Method ◽  
Die Design ◽  
High Quality ◽  
Weldability Tests ◽  
Welding Stress ◽  
Porthole Die ◽  
Extrusion Welding ◽  
Wide Range ◽  
Mg Content

In the work, an original method and a special modified device is presented enabling to determine welding conditions of hard deformable aluminium alloys. The main advantage of the proposed method is that it simulates conditions occurring in the welding chamber of the porthole dies. The weldability tests were performed for 5754 (3,5% Mg) and 5019 (5,5% Mg) alloys, in a wide range of temperatures and pressures. The microstructure and joints strength were examined. The welding conditions of AlMg alloys that allowed obtaining high-quality joints were determined. The obtained welding stress values will be the basis for extrusion porthole die design.

Pituitary and testicular responses in sexually mature bulls after intravenous injections of graded doses of LH-releasing hormone

1984 ◽  
Vol 103 (3) ◽  
pp. 371-376 ◽  
Author(s):  
M. J. D'Occhio ◽  
B. P. Setchell
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Anterior Pituitary Gland ◽  
Limiting Factor ◽  
Releasing Hormone ◽  
Intravenous Injections ◽  
Gonadotrophin Secretion ◽  
Lh Release ◽  
Lh Releasing Hormone ◽  
Sexually Mature

ABSTRACT The capacity of the anterior pituitary gland and testes in mature bulls (705±9 (s.e.m.) kg body wt, n = 4) to respond to graded doses of LH-releasing hormone (LHRH) was assessed relative to endogenous profiles of LH and testosterone secretion. Endogenous hormone profiles were determined by bleeding bulls at 20-min intervals for 12 h. Responses to LHRH were assessed on successive days after single intravenous injections of 1, 5, 10, 50 or 100 ng LHRH/kg body wt. Blood samples were taken at −40, −20, 0, 10, 20, 30, 40, 60 and 120 min relative to LHRH injection. During a 12-h bleed bulls showed spontaneous pulses of LH and testosterone which had peak amplitudes of 2·6±0·5 μg/l and 44·5 ± 7·1 nmol/l respectively. Respective peak LH (μg/l) and testosterone (nmol/l) responses to LVRH were as follows: 1 ng LHRH (3·0±0·7: 47·3±4·1); 5 ng LHRH (8·0±1·2; 52·8 ± 6·2); 10 ng LHRH (11·1±2·3; 57·7 ± 9·1); 50 ng LHRH (19·2±2·8; 47·9±8·6); 100 ng LHRH (19·1±4·7; 43·9 ±6·4). A dose of 1 ng LHRH/kg produced LH and testosterone responses which were comparable in amplitude to spontaneous peaks in the respective hormone. There was a linear (y = 0·28x+5·72; r = 0·81) increase in the LH response to doses of LVRH between 1 and 50 ng/kg; corresponding testosterone responses showed no relationship with the dose of LHRH. The capacity of the anterior pituitary gland to release amounts of LH eight to ten times in excess of those secreted during spontaneous peaks suggests that (1) there exists a large releasable store of LH in the anterior pituitary gland and (2) hypothalamic LHRH is a limiting factor in gonadotrophin secretion. In contrast to LH release, the androgenic response of the testes to acute gonadotrophic stimulation is determined largely by prevailing steroidogenic activity. J. Endocr. (1984) 103, 371–376

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