scholarly journals Degenerative Changes in The Putamen of Growing Rats Induced by Maternal Excess Iron Exposure

2021 ◽  
Vol 13 (2) ◽  
pp. 119-133
Author(s):  
AYMAN AMER ◽  
Mohamed Saleh ◽  
Mohamed Mohamed ◽  
Omnia Ismail
Keyword(s):  
Degenerative Changes ◽  
Excess Iron ◽  
Growing Rats

Electron Microscopic and Isozyme Study of a Case of Ochronosis

1972 ◽  
Vol 30 ◽  
pp. 88-89
Author(s):  
Jay W. Cha ◽  
Perry J. Melnick
Keyword(s):  
Benzene Ring ◽  
Enzyme System ◽  
Homogentisic Acid ◽  
Degenerative Changes ◽  
Acid Oxidase ◽  
Electron Microscopic ◽  
Tyrosine Metabolism ◽  
Collagenous Tissues

Hereditary ochronosis in very few cases has been examined electron microscopically or histochemically. In this disease homogentisic acid, a normal intermediary of tyrosine metabolism, forms in excessive amounts. This is believed to be due to absence or defective activity of homogentisic acid oxidase, an enzyme system necessary to break the benzene ring and to further break it down to fumaric and acetoacetic acids. Ochronotic pigment, a polymerized form of homogentisic acid, deposits mainly in mesenchymal tissues. There has been a question whether the pigment originates from the collagenous tissues, or deposits passively, where in contrast to melanin it induces degenerative changes.

MR-derived CT-like Images for the Assessment of Acute Vertebral Fractures and Osseous Degenerative Changes in the Thoracolumbar Spine

2020 ◽  
Author(s):  
Benedikt J. Schwaiger ◽  
Charlotte Schneider ◽  
Sophia Kronthaler ◽  
Christoph Böhm ◽  
Julian Zapf ◽  
...  
Keyword(s):  
Vertebral Fractures ◽  
Thoracolumbar Spine ◽  
Degenerative Changes

Testosterone-dependent changes in neurons of hypothalamic arcuate nucleus and reversibility of these changes by modeled male hypogonadism

2017 ◽  
pp. 21-30
Author(s):  
А.В. Дробленков ◽  
Л.Г. Прошина ◽  
Ю.Н. Юхлина ◽  
А.А. Байрамов ◽  
П.Д. Шабанов ◽  
...  
Keyword(s):  
Replacement Therapy ◽  
Nerve Cell ◽  
Arcuate Nucleus ◽  
Degenerative Changes ◽  
Control Group ◽  
Male Hypogonadism ◽  
Nissl Staining ◽  
Neuron Body ◽  
Androgen Synthesis ◽  
Reactive Changes

Актуальность. Значение недостаточности тестостерона для структурного гомеостазиса нейронов, регулирующих выработку гонадотропин-рилизинг гормона (ГнРГ) и синтезирующих данный гормон, мало изучены. Цель. Установить реактивные изменения, количество рецепторов к андрогенам (АР) и особенности их распределения в нейронах медиального аркуатного ядра гипоталамуса (МАЯ) при экспериментальном гипогонадизме, а также обратимость этих изменений после восстановительной терапии тестостероном. Методы. У самцов крыс Вистар (16 особей) моделировали гипогонадизм путем удаления одной гонады на 2-3 день постнатальной жизни и исследовали гистологические срезы каудальной части МАЯ у молодых животных (4 мес.) при отсутствии и осуществлении заместительной терапии. Контрольную группу составляли интактные самцы аналогичного возраста (8 особей). В середине левосторонней части МАЯ на площади 0,01 мм определяли реактивные изменения клеток и площадь тел малоизмененных нейронов (после окрашивания срезов методом Ниссля), а также число и долю тел нервных клеток, различавшихся по степени экспрессии АР. Результаты. Установлено, что нейроны МАЯ содержат большое количество АР, распределенных в различных частях их тела. При гипогонадизме происходит перераспределение АР и снижение степени их экспрессии (количества). Сгущение АР в области оболочки ядра и плазмолеммы, образование конгломератов в ядре и цитоплазме было характерно для нейронов с умеренной экспрессией. В цитоплазме и в области плазматической мембраны рецепторы отсутствовали у клеток со слабой и очень низкой экспрессией. Снижение степени экспрессии АР при гипогонадизме сопряжено с уменьшением площади тела и гибелью части нейронов. Заключение. Выявленные дегенеративные тестостерон-зависимые изменения нейронов МАЯ, которые синтезируют ГнРГ или пептиды, влияющие на его выработку, могут обусловить уменьшение высвобождения гонадолиберина, вторичное снижение синтеза андрогенов и реализацию морфофункциональных проявлений его вторичного дефицита. Заместительная терапия частично компенсирует дегенеративные изменения нейронов, восстанавливает интенсивность экспрессии АР, однако не влияет на процесс гибели нервных клеток. Background. Importance of testosterone deficiency for structural homeostasis of the neurons regulating production of gonadotropin-releasing hormone (GnRH) and synthesizing this hormone is insufficiently understood. Aim. To determine reactive changes, quantity of androgens receptors (AR), and features of their distribution in neurons of hypothalamic medial arcuate nucleus (MAN) in experimental hypogonadism and reversibility of these changes by restorative therapy with testosterone. Methods. Hypogonadism was modeled in 16 Wistar rats by removing one gonad on postnatal days 2-3, and histological sections of caudal MAN were examined in young, 4-month old animals with and without a replacement therapy. The control group consisted of 8 age-matched intact males. Cell reactive changes, areas of slightly changed neuron bodies (Nissl staining of sections), and the number and proportion of nerve cell bodies differing in the degree of AR expression were determined in the middle left-sided part of MAN, on an area of 0.01 mm. Results. MAN neurons contained a large quantity of AR distributed in different parts of the neuron body. In hypogonadism, AR redistributed and their expression (quantity) decreased. Condensation of AR in the region of nucleo- and plasmolemma and formation of conglomerates in the nucleus and cytoplasm were characteristic of neurons with moderate expression. In the regions of cytoplasm and plasma membrane, the receptors were absent in cells with low and very low expression. The reduced AR expression in hypogonadism was associated with a decreased neuron body area and death of a part of neurons. Conclusions. The identified degenerative changes in the testosterone-dependent neuronal MAN that synthesize GnRH or peptides affecting the GnRH production may decrease the release of GnRH, cause a secondary decrease in the androgen synthesis, and mediate morphological and functional manifestations of GnRH secondary deficit. The replacement therapy partially compensated for degenerative changes in neurons and restored the intensity of AR expression, however, it did not influence the process of nerve cell death.

A Study on the Bioavailability of Organic Ca in Growing Rats

2012 ◽  
Vol 41 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Mi-Na Park ◽  
Su-Jung Cho ◽  
Hee-Kyong Kim ◽  
Jae-Hong Kim ◽  
Min-Ho Kim ◽  
...  
Keyword(s):  
Growing Rats

Relationship of degenerative changes of the temporomandibular joint (TMJ) with the angle of eminentia

2006 ◽  
Vol 33 (9) ◽  
pp. 638-645 ◽  
Author(s):  
T. R. JASINEVICIUS ◽  
M. A. PYLE ◽  
S. NELSON ◽  
J. A. LALUMANDIER ◽  
K. J. KOHRS ◽  
...  
Keyword(s):  
Temporomandibular Joint ◽  
Degenerative Changes ◽  
Relationship Of

scholarly journals Detection of Degenerative Changes on MR Images of the Lumbar Spine with a Convolutional Neural Network: A Feasibility Study

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 902
Author(s):  
Nils Christian Lehnen ◽  
Robert Haase ◽  
Jennifer Faber ◽  
Theodor Rüber ◽  
Hartmut Vatter ◽  
...  
Keyword(s):  
Neural Network ◽  
Lumbar Spine ◽  
Diagnostic Accuracy ◽  
Nerve Root ◽  
Spinal Canal ◽  
Spinal Canal Stenosis ◽  
Degenerative Changes ◽  
High Diagnostic Accuracy ◽  
Canal Stenosis ◽  
Disc Herniations

Our objective was to evaluate the diagnostic performance of a convolutional neural network (CNN) trained on multiple MR imaging features of the lumbar spine, to detect a variety of different degenerative changes of the lumbar spine. One hundred and forty-six consecutive patients underwent routine clinical MRI of the lumbar spine including T2-weighted imaging and were retrospectively analyzed using a CNN for detection and labeling of vertebrae, disc segments, as well as presence of disc herniation, disc bulging, spinal canal stenosis, nerve root compression, and spondylolisthesis. The assessment of a radiologist served as the diagnostic reference standard. We assessed the CNN’s diagnostic accuracy and consistency using confusion matrices and McNemar’s test. In our data, 77 disc herniations (thereof 46 further classified as extrusions), 133 disc bulgings, 35 spinal canal stenoses, 59 nerve root compressions, and 20 segments with spondylolisthesis were present in a total of 888 lumbar spine segments. The CNN yielded a perfect accuracy score for intervertebral disc detection and labeling (100%), and moderate to high diagnostic accuracy for the detection of disc herniations (87%; 95% CI: 0.84, 0.89), extrusions (86%; 95% CI: 0.84, 0.89), bulgings (76%; 95% CI: 0.73, 0.78), spinal canal stenoses (98%; 95% CI: 0.97, 0.99), nerve root compressions (91%; 95% CI: 0.89, 0.92), and spondylolisthesis (87.61%; 95% CI: 85.26, 89.21), respectively. Our data suggest that automatic diagnosis of multiple different degenerative changes of the lumbar spine is feasible using a single comprehensive CNN. The CNN provides high diagnostic accuracy for intervertebral disc labeling and detection of clinically relevant degenerative changes such as spinal canal stenosis and disc extrusion of the lumbar spine.

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