Morphometric study of the platform elements of Amydrotaxis praejohnsoni n. sp. (Lower Devonian, conodonts, Nevada)

1989 ◽  
Vol 63 (3) ◽  
pp. 349-355 ◽  
Author(s):  
Michael A. Murphy ◽  
Kathleen B. Springer

The platform element of the conodont Amydrotaxis praejohnsoni n. sp. shows statistically significant morphological changes from the base to the top of the delta Zone (Lower Devonian). The changes occur particularly in mean denticle number, height and character of the anterior denticles, and shape of the basal cavity. The earliest forms have fewer denticles ( = 7.1), an enlarged, high anterior denticle, and a broadly flared posterior basal cavity, whereas late forms have more denticles ( = 9.4), equal-sized anterior denticles, and a narrow posterior basal cavity. There is no stasis phase in the species history, but rather a mosaic pattern in which the observed changes in the character states are seemingly independent of each other and proceed at variable rates.

1980 ◽  
Vol 61 (4) ◽  
pp. 26-28
Author(s):  
M. V. Uglova ◽  
V. N. Shlyapnikov ◽  
V. V. Sergeev ◽  
A. U. Zalmunin ◽  
E. A. Taikov

Morphometric study of human cardiac neurocytes in myocardial infarction and atherosclerosis made it possible to establish that myocardial infarction causes adaptive (hypertrophic) changes in the intramural nervous system of the heart, especially pronounced on the first day of the course of the infarction; with atherosclerosis, the changes are characterized by a direction towards atrophic processes.


2021 ◽  
pp. 484-488
Author(s):  
Sidelnikova

A morphometric study of liver changes at different invasive doses was conducted in rodents (Oryctolagus cuniculus). In a comparative aspect, the thickness of connective tissue formed around the portal tracts and the thickness of cellular infiltrates in the same area were studied at an invasive dose of 100, 50 and 10 metacercariae of Ophistorchis felineus (Rivolta, 1884). The experiment was conducted on sexually mature male rabbits at the age of 6 months, in each observation group of 10 individuals. Clinically healthy animals were infested with Ophistorchis felineus per os metacercariae once. The intermediate stage of the parasite was isolated from a dead fish (ide, Leuciscus idus (Linnaeus, 1758) and dace fish, Leuciscus leuciscus) obtained from the Tom River in Tomsk. The invasion that took place after 1 month was confirmed by a positive analysis of feces for parasite eggs by the Ragaser and KatoMiura methods. The animals were sacrificed after 5 weeks from the period of infestation. Histological preparations of the liver were made, stained with hematoxylin and eosin, according to Van Gieson. Histological preparations were studied by light microscopy with morphometry. The results obtained characterize a twofold change in the morphometric parameters of connective tissue thickness and cellular infiltration around the portal tracts of the liver lobes with an increase in the invasive dose.


Author(s):  
О.В. Казаков ◽  
А.Ф. Повещенко ◽  
А.В. Кабаков ◽  
О.В. Повещенко ◽  
Д.Н. Стрункин ◽  
...  

Цель исследования - выявление структурных преобразований тимуса самок крыс Вистар при хирургическом лечении рака молочной железы и при химиотерапии. Методика. Рак молочной железы (РМЖ) индуцировали введением N-метил-N-нитрозомочевины 5 раз с интервалом 7 сут подкожно в область 2-й молочной железы справа. Оперативное лечение РМЖ проводили через 6 мес от момента индукции РМЖ. Курс химиотерапии проводили по схеме CMF. Гистологическое исследование тимуса и опухоли молочной железы проводили по стандартной методике. Методом точечного счёта производили морфометрию срезов и подсчет клеточных элементов в опухоли и структурно-функциональных зонах тимуса. Результаты. При РМЖ без лечения выявлены структурные признаки акцидентальной инволюции тимуса. После оперативного лечения РМЖ акцидентальная инволюция тимуса менее выражена по сравнению с химиотерапией. После оперативного лечения РМЖ, как и в группе РМЖ без лечения, в тимусе сохраняется уменьшение площади коркового вещества. По сравнению с РМЖ без лечения в тимусе уменьшалась площадь железистых эпителиальных образований, увеличилась плотность расположения клеточных элементов в корковом веществе. В структурных зонах тимуса увеличивалось количество макрофагов, снижалось количество клеток с пикнотичными ядрами. После химиотерапии, по сравнению с резекцией опухоли МЖ, в тимусе выявлены структурные признаки прогрессирования процесса инволюции. В тимусе уменьшена площадь соединительно-тканных элементов, снижено количество митозов в субкапсулярной зоне коркового вещества. Во всех исследуемых зонах увеличено количество клеток с пикнотичными ядрами и уменьшено число макрофагов. Заключение. После оперативного лечения РМЖ акцидентальная инволюция тимуса проявляется в менее выраженной форме, чем в группе с РМЖ без лечения. После химиотерапии РМЖ, по сравнению с оперативным лечением РМЖ, морфологические перестройки в тимусе свидетельствуют о снижении активности лимфоидного и эпителиального компонентов и увеличении числа гибнущих клеток. Aim. To identify structural changes in the thymus of female Wistar rats during surgical treatment of breast cancer or with chemotherapy. Methods. Breast cancer (BC) was induced by subcutaneous injection of N-methyl-N-nitrosourea into the second right breast 5 times at 7 day intervals. Resection of BC was performed 6 mos after BC induction, or chemotherapy was administered according to the CMF scheme. Histological examination of the thymus and breast tumor was performed according to a standard method. Morphometric study of sections and counting cell elements in the tumor and in structural and functional areas of the thymus were performed by point counting. Results. In untreated BC, structural signs of accidental thymus involution were evident. There was an increase in the area of connective tissue elements and of glandular epithelial tumors. After surgical treatment of BC, accidental thymus involution was less pronounced than after chemotherapy. Also after surgical treatment, as in the case of untreated BC, the thymus cortical substance remained decreased. Compared with untreated BC, the area of glandular epithelial tumors in the thymus decreased, and the density of cellular elements in the cortical substance increased. In the structural zones of the thymus, the number of macrophages increased, and the number of cells with pyknotic nuclei decreased. After chemotherapy, in comparison with surgical treatment, structural signs of involution of the thymus were evident. In the thymus, the area of connective tissue elements was reduced, and the number of mitotically dividing cells in the subcapsular zone of the cortical substance was reduced. In all the zones of the thymus, the number of cells with pyknotic nuclei increased, and the number of macrophages decreased. Conclusion. After surgical treatment of BC, accidental thymus involution was less pronounced than in the untreated group. After chemotherapy, compared with surgical treatment of BC, morphological changes in the thymus may indicate a decrease in the activity of the lymphoid and epithelial components and an increase in the number of dying cells.


1987 ◽  
Vol 61 (3) ◽  
pp. 583-594 ◽  
Author(s):  
Michael A. Murphy ◽  
M. Kemal Cebecioglu

This paper presents a morphometric study of the conodont genus Ancyrodelloides. It is one of a series of such papers whose goal is to increase the precision of correlation within the Lower Devonian by refining the taxonomic basis of its biostratigraphic units. Ancyrodelloides species are confined to the delta Zone and may be used to divide it into three parts. Morphometrics verify the species rank of A. eleanorae, A. limbacarinatus, A. trigonicus, and A. transitans. Ancyrodelloides delta and A. omus are retained as species on qualitative grounds, but need larger samples for statistical evaluation. Ancyrodelloides asymmetricus and A. kutscheri are classified as varieties, but lack adequate samples.


2018 ◽  
Vol 45 (1-2) ◽  
pp. 18-26 ◽  
Author(s):  
Antoine Brangier ◽  
Sébastien Celle ◽  
Frédéric Roche ◽  
Olivier Beauchet ◽  
Guylaine Ferland ◽  
...  

Background: Vitamin K antagonists (VKAs) are commonly used for their role in haemostasis by interfering with the vitamin K cycle. Since vitamin K also participates in brain physiology, this voxel-based morphometric study aimed to determine whether the duration of exposure to VKAs correlated with focal brain volume reduction in older adults. Methods: In this exposed/unexposed (1: 2) study nested within the GAIT (Gait and Alzheimer Interactions Tracking) cohort, 18 participants exposed to VKA (mean age 75 ± 5 years; 33.3% female; mean exposure 2,122 ± 1,799 days) and 36 matched participants using no VKA (mean age 75 ± 5 years; 33.3% female) underwent MRI scanning of the brain. Cortical grey and white matter volumes were automatically segmented using statistical parametric mapping. Age, gender, educational level, history of atrial fibrillation, type of MRI, and total intracranial volume were included as covariables. Results: The duration of exposure to VKA correlated inversely across the whole brain with the subvolumes of two clusters in the grey matter (right frontal inferior operculum and right precuneus) and one cluster in the white matter (left middle frontal gyrus). In contrast, the grade of white matter hyperintensities did not differ according to the use of VKA. Conclusion: We found focal atrophies in older adults exposed to VKA. These findings provide new insights elucidating the effects of VKAs on brain health and function in older adults.


2006 ◽  
Vol 209 (3) ◽  
pp. 381-392 ◽  
Author(s):  
Sergio Morini ◽  
Mark Braun ◽  
Paolo Onori ◽  
Luca Cicalese ◽  
George Elias ◽  
...  

2016 ◽  
Vol 33 (02) ◽  
pp. 090-095
Author(s):  
M. Benigno ◽  
E. Amstalden ◽  
E. Liberti ◽  
N. Leal ◽  
K. Rodrigues ◽  
...  

Abstract Introduction: To check the morphological changes of the masseter muscle after surgical extraction of inferior molar teeth. Methods: 24 Wistar rats had samples of their masseter muscles analysed in the Optical Microscope (OM). The rats were randomly divided into three groups as follows: GI-15, GII-30, GII-60 days after surgical extraction of inferior molar teeth. Each group had 5 experimental and 3 normal control rats for OM observation. The OM allowed the morphometric study of the masseter muscle. The morphometric study was based on the measurement of the fiber's area by AXION-VISION software. ANOVA test was applied for data analysis. Results: No alteration was detected in all morphometric analysis of the masseter muscle. Conclusion: The masseter muscle adapts to the occlusal modiication caused by the extraction of the molar teeth during the analysed periods.


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