scholarly journals Heterochromatin Dynamics in Response to Environmental Stress in Amazonian Fish

2021 ◽  
Author(s):  
Daniele Aparecida Matoso ◽  
Maelin da Silva ◽  
Hallana Cristina Menezes da Silva ◽  
Eliana Feldberg ◽  
Roberto Ferreira Artoni

Transcriptionally inactive portions of genomic DNA, condensed with histones and architectural proteins, are known as heterochromatic regions, often positive C band. The advent of epigenetics and new methodological approaches, showed that these regions are extremely dynamic and responsive to different types of environmental stress. The relationship of the constitutive heterochromatin with the transposable elements inactivation, especially from the Rex family, seems to be a frequent condition in fish. In this manuscript we review the existing knowledge of the nature and function of these genomic regions, based on species-based studies, with a focus on species of fish from the Amazon region.

Blood ◽  
1948 ◽  
Vol 3 (7) ◽  
pp. 729-754 ◽  
Author(s):  
WILLIAM N. VALENTINE ◽  
CHARLES G. CRADDOCK ◽  
JOHN S. LAWRENCE

Abstract The hormonal control through the hypophyseo-adrenal cortical system of lymphoid tissue structure and function is an important concept. We cannot at the present time regard that the concept is established fact. Final judgment must await additional work and the clarification of some of the inconsistencies which appear to exist. It seems reasonable that lymphoid tissue is one of the end organs of adrenal cortical hormone and that it may perhaps play a role in the response of the organism to stress. It seems quite clear that the sugar hormone of the adrenal cortex is capable of producing structural alterations in lymphoid tissue. Change in thoracic duct lymphocyte numbers as a result of augmentation in the amount of available adrenal cortical hormone is at present controversial. Experiments in this laboratory have failed to demonstrate it. The production of lymphopenia, at least in some species and possibly in man, by increasing available sugar hormone is supported by some evidence. The exact mechanism of production of lymphopenia is open to question, its relationship to changes in lymphoid tissue structure being one of inference. The converse situation—absolute lympocytosis resulting from deprivation of adrenal cortical hormone—is the subject of controversial reports. At best, it must be admitted that relatively slight alterations from the accepted normal range of lymphocyte values occur in the adrenal insufficient organism. Changes in plasma gamma globulins and antibody titers associated with changes in the amount of available cortical hormone are reported. It should be clarified whether such changes have necessarily resulted from lymphocyte dissolution or are related to other of the variegated actions of adrenal cortical hormone. The relationship of adrenal cortical hormone to lymphoid tissue and lymphocytes and the relationship of the latter to the response of the organism to stress must indeed be complex. It is reasonably well established that the life span of the lymphocyte is very short indeed1,58,22 and each lymphocyte presumably liberates its metabolically important contents within a few hours at the most. If stress continues for any period of time, as often it does, it is difficult to visualize the wisdom of interfering with the production of metabolically vital substances in order to secure the transient benefits of lymphoid tissue dissolution. It is also somewhat difficult to regard as proved that the various changes reported after hormone augmentation or deprivation necessarily represent the normal mechanism by which these factors are regulated and kept within physiologic limits. More investigations are required to answer such questions and to further elucidate the interrelationship of the adrenal cortex and lymphoid tissues.


Open Heart ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. e000831 ◽  
Author(s):  
Melissa Suzanne Burroughs Peña ◽  
Katrina Swett ◽  
Robert C Kaplan ◽  
Krista Perreira ◽  
Martha Daviglus ◽  
...  

ObjectiveTo describe the relationship of household secondhand smoke (SHS) exposure and cardiac structure and function.MethodsParticipants (n=1069; 68 % female; age 45–74 years) without history of tobacco use, coronary artery disease or severe valvular disease were included. Past childhood (starting at age <13 years), adolescent/adult and current exposure to household SHS was assessed. Survey linear regression analyses were used to model the relationship of SHS exposure and echocardiographic measures of cardiac structure and function, adjusting for covariates (age, sex, study site, alcohol use, physical activity and education).ResultsSHS exposure in childhood only was associated with reduced E/A velocity ratio (β=−0.06 (SE 0.02), p=0.008). SHS exposure in adolescence/adult only was associated with increased left ventricular ejection fraction (LVEF) (1.2 (0.6), p=0.04), left atrial volume index (1.7 (0.8), p=0.04) and decreased isovolumic relaxation time (−0.003 (0.002), p=0.03). SHS exposure in childhood and adolescence/adult was associated with worse left ventricular global longitudinal strain (LVGLS) (two-chamber) (0.8 (0.4), p= 0.049). Compared with individuals who do not live with a tobacco smoker, individuals who currently live with at least one tobacco smoker had reduced LVEF (−1.4 (0.6), p=0.02), LVGLS (average) (0.9 (0.40), p=0.03), medial E′ velocity (−0.5 (0.2), p=0.01), E/A ratio (−0.09 (0.03), p=0.003) and right ventricular fractional area change (−0.02 (0.01), p=0.01) with increased isovolumic relaxation time (0.006 (0.003), p=0.04).ConclusionsPast and current household exposure to SHS was associated with abnormalities in cardiac systolic and diastolic function. Reducing household SHS exposure may be an opportunity for cardiac dysfunction prevention to reduce the risk of future clinical heart failure.


2019 ◽  
Vol 8 (9) ◽  
pp. 214-225
Author(s):  
Nongmeikapam Premika Devi

The present study examines the relationship of depression and the neuropsychologicalfunction of attention, planning and auditory verbal learning and memory among individualswith HIV/AIDS. 200 subjects who were HIV/AIDS positive (100 males and 100 females) andwere within age range of 20 to 50 years and minimum education level of 8th standard weretaken. The result indicates that Depression slows down the performance of attention; alsodepression most likely decreases the function of auditory verbal learning and memory


Perichoresis ◽  
2015 ◽  
Vol 13 (1) ◽  
pp. 75-97
Author(s):  
Laura Verner

Abstract An integral method of keeping a non-conforming community functioning is the construction and up keep of networks, as this web of connections provided security and protection with other non-conformists against the persecuting authorities. The non-conforming Catholic community of Elizabethan England (1558-1603) established various networks within England and abroad. This article is based on research that examines the network of Catholics in the Elizabethan Midlands in order to understand both its effectiveness and the relationship of the local and extended Catholic community with one another. The construction, function and result of these networks will be surveyed over several categories of networks, such as local, underground, clerical and exile. Members of the Midland Catholic community travelled to others areas of the British Isles and Europe to gather spiritual and material support for their faith, sent their children abroad for religious education, and resettled abroad creating in this wake a larger and complex international network. The main objective of this exercise is to show the dynamic and function of the network, and understand the impact it had at the local level for Midland Catholics.


Author(s):  
Мархат Увайсовна Яхьяева

В статье предпринята попытка соотношения таких юридических категорий, как «уголовное преследование» и «функция обвинения». Проводится компаративный анализ обвинения и подозрения как неотъемлемых элементов деятельности органов, осуществляющих уголовное преследование. The article attempts to correlate such legal categories as “criminal prosecution” and “function of accusation”. A comparative analysis of charges and suspicions as integral elements of the activities of bodies carrying out criminal prosecution is carried out.


1985 ◽  
Vol 73 (1) ◽  
pp. 299-310
Author(s):  
J.S. Hyams

Axonemes from the heterosporous water fern Marsilea vestita were fixed in the presence of tannic acid and examined by thin-section electron microscopy. Transverse sections revealed the normal 9+2 configuration except for the absence of the outer of the two dynein arms. Both arms were normally preserved in parallel preparations of Chlamydomonas axonemes. Isolated dynein from the ciliated protozoon Tetrahymena bound to Marsilea axonemes at the site normally occupied by the outer arm. Dynein binding was partially reversed by ATP as judged by both electron microscopy and polyacrylamide gel electrophoresis. This system should provide a valuable insight into the biochemistry and function of the inner dynein arm and the relationship of the two arms to motility in more conventionally equipped axonemes.


2019 ◽  
Vol 9 (1) ◽  
pp. 16-21
Author(s):  
DM Arman ◽  
Sheikh Muhammad Ekramullah ◽  
Sudipta Kumer Mukherjee ◽  
Joynul Islam ◽  
Mirza Hafizur Rashid ◽  
...  

Object: The objective of this study was to determine the relationship of the location of the ventricular catheter tip and function of the ventriculoperitoneal shunt. Methods: This prospective observational study included 140 patients from a single institution who underwent a ventriculoperitoneal shunt procedure in which a new ventricular catheter was placed between September, 2013 and September 2016. Data abstracted for each patient included age, sex, diagnosis, site and side of ventricular catheter placement. Postoperative CT scan images were reviewed for accuracy of ventricular catheter placement. Patients were followed up over 2 ½ to 4 ½ years.63 patients were available for follow up. We lost communication with rest of the patients. The relationship of the location of the ventricular catheter tip and function of the ventriculoperitoneal shunt was analyzed in 63 patients. Results: There were 140 patients included in the study; accuracy ventricular catheter tip placement were 55 (39.28%) using freehand technique. VP shunt functioned well in 43 (68.25%) of 63 patients. Among the 43 patients with well functioning shunt ,19 were in accurate group ,7 were in suboptimal group and 17 were in inaccurate group.26 patients (41.27%) had good outcome with normal development and normal IQ Conclusions: Mechanical malfunction and infection are the most significant problems associated with shunts for the treatment of hydrocephalus. Above all, a significant proportion of shunt failure was due to obstruction of the ventricular catheter, and accurate placement of the shunt catheter is highly important to reduce the incidence of shunt malfunction. Bang. J Neurosurgery 2019; 9(1): 16-21


2000 ◽  
Vol 2 (2) ◽  
pp. 117-131 ◽  
Author(s):  
Kathleen Michael

In the realm of muscle atrophy research, many studies address minute details of molecular function but few examine the effects of atrophy in terms of mobility, strength, endurance, and performance of activities of daily living. The relationship between impairment and functional limitation is the focus of this research review. A wide array of studies constitute this area of inquiry, including investigations as diverse and widely disparate as molecular chemistry and space travel and populations as different as rats, healthy young men, and elderly women. Thirty-four studies were selected based on their fit with the Enabling-Disabling Model. Three paradigms of atrophy and function emerged. Adaptation reflects the plastic nature of muscle when placed under certain conditions, ranging from disuse to high-resistance exercise. Injury/loss describes damage to muscle tissue from ischemia, medications, or reloading or reperfusion trauma. Also in this category is the loss of muscle that is seen with aging. Integrity relates to the muscle’s tendency to protect itself and maintain structural adjacencies and cellular proportions. Based on the 3 muscle research paradigms, the relationship of muscle atrophy to function is portrayed as a bidirectional interaction wherein form and function have an influence on each other by way of physical changes, including those of adaptation, injury/loss, or integrity. A conceptual model is constructed to reflect this relationship.


1996 ◽  
Vol 76 (3) ◽  
pp. 887-926 ◽  
Author(s):  
H. A. Fozzard ◽  
D. A. Hanck

Cardiac and nerve Na channels have broadly similar functional properties and amino acid sequences, but they demonstrate specific differences in gating, permeation, ionic block, modulation, and pharmacology. Resolution of three-dimensional structures of Na channels is unlikely in the near future, but a number of amino acid sequences from a variety of species and isoforms are known so that channel differences can be exploited to gain insight into the relationship of structure to function. The combination of molecular biology to create chimeras and channels with point mutations and high-resolution electrophysiological techniques to study function encourage the idea that predictions of structure from function are possible. With the goal of understanding the special properties of the cardiac Na channel, this review examines the structural (sequence) similarities between the cardiac and nerve channels and considers what is known about the relationship of structure to function for voltage-dependent Na channels in general and for the cardiac Na channels in particular.


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