Understanding the molecular mechanisms of transcriptional bursting

2021 ◽  
Vol 23 (38) ◽  
pp. 21399-21406
Author(s):  
Alena Klindziuk ◽  
Anatoly B. Kolomeisky
Keyword(s):  
Molecular Mechanisms ◽  
Point Of View ◽  
Physical Chemical ◽  
Bursting Phenomena ◽  
Transcriptional Bursting

Microscopic origins of transcriptional bursting phenomena are discussed from the physical–chemical point of view.

Constraints to the modelling of diet selection and intake in the grazing ruminant

1996 ◽  
Vol 47 (2) ◽  
pp. 257 ◽  
Author(s):  
H Dove
Keyword(s):  
Decision Support ◽  
Diet Selection ◽  
Point Of View ◽  
Botanical Composition ◽  
Factors Influencing ◽  
Major Constraint ◽  
Physical Chemical ◽  
Herbage Intake ◽  
Spatial Terms ◽  
Future Work

The interaction of grazing animals and their pasture generates substantial income for Australia, so that an interest in modelling the processes involved can be justified readily. Based on a brief review of the factors influencing diet selection, it is suggested that, from the point of view of modelling the process, a major constraint has been the availability of accurate and convenient methods for estimating the botanical composition of the consumed diet. It is also suggested that there is a need in future work to define more adequately the available herbage in botanical, physical, chemical and spatial terms, and to conduct experiments in which factors influencing selection are examined in an unconfounded way. It is further suggested that, while the idea of fixed preference or selection coefficients for particular species is attractive from a modelling standpoint, available evidence does not support the concept. Factors influencing herbage intake are then discussed, particularly in relation to the interaction between the degree of rumen fill and the animal's capacity to use energy. The manner in which this interaction has been used in the modelling of intake is then described briefly and the modeling of diet selection and intake within the decision-support system GrazFeed is presented by way of example. Finally, the constraints associated with model validation are discussed briefly, especially in relation to the need in future work to define more adequately the characteristics of the pasture on offer.

COVID-19 and diabetes mellitus: potential metabolic associations

2021 ◽  
Vol 21 ◽  
Author(s):  
Pedro Henrique Abreu da Silva ◽  
Andressa Santos Garcia ◽  
Fábio Aguiar Alves ◽  
André Luis Souza dos Santos ◽  
Cátia Lacerda Sodré
Keyword(s):  
Diabetes Mellitus ◽  
Viral Entry ◽  
Molecular Mechanisms ◽  
Renin Angiotensin System ◽  
Cell Receptor ◽  
Protective Role ◽  
Infection Process ◽  
Point Of View ◽  
Diabetic Patients ◽  
Viral Binding

: The COVID-19 pandemic turned the SARS-CoV-2 into the main target of scientific research all around the world. Many advances have already been made, but there is still a long way to go to solve the molecular mechanisms related to the process of the SARS-CoV-2 infection, as well as the particularities of the disease, its course and the complex host-pathogen relationships. However, a lot has been theorized and associated with COVID-19, like the worst prognosis of the disease among individuals with some comorbidities, like diabetes mellitus. In this perspective, diabetic patients are repeatedly associated with more severe cases of COVID-19 when compared to non-diabetic patients. Even though ACE2 (angiotensin-converting enzyme 2) was recognized as the host cell receptor for both binding and entering of SARS-CoV-2 particles, it was also pointed out that this enzyme plays an important protective role against pulmonary damage. Therefore, paradoxically as it may seem, the low baseline level of this receptor in people with diabetes is directly linked to a more expressive loss of ACE2 protective effect, which could be one of the possible factors for the worst prognosis of COVID-19. Still, COVID-19 may also have a diabetogenic effect. From this point of view, the main topics that will be highlighted are (i) the mechanism of the viral entry, with special attention to the cellular receptor (ACE2) and the viral binding protein (spike), (ii) the relationship among the renin-angiotensin system, the infection process and the patients' prognosis, (iii) the glucose control and the medicines used in this event, and (iv) a brief analysis on diabetes triggered by COVID-19.

Transcription in Living Cells: Molecular Mechanisms of Bursting

2020 ◽  
Vol 89 (1) ◽  
pp. 189-212 ◽  
Author(s):  
Joseph Rodriguez ◽  
Daniel R. Larson
Keyword(s):  
Gene Regulation ◽  
Rna Synthesis ◽  
Molecular Mechanisms ◽  
Gene Activation ◽  
Living Cells ◽  
Single Locus ◽  
Individual Gene ◽  
Technological Advances ◽  
Transcriptional Bursting ◽  
Cell Data

Transcription in several organisms from certain bacteria to humans has been observed to be stochastic in nature: toggling between active and inactive states. Periods of active nascent RNA synthesis known as bursts represent individual gene activation events in which multiple polymerases are initiated. Therefore, bursting is the single locus illustration of both gene activation and repression. Although transcriptional bursting was originally observed decades ago, only recently have technological advances enabled the field to begin elucidating gene regulation at the single-locus level. In this review, we focus on how biochemical, genomic, and single-cell data describe the regulatory steps of transcriptional bursts.

Effects of Huangqi (Hex) on Inducing Cell Differentiation and Cell Death in K562 and HEL Cells¤

2004 ◽  
Vol 36 (3) ◽  
pp. 211-217 ◽  
Author(s):  
Xiao-Dong Cheng ◽  
Chun-Hui Hou ◽  
Xue-Jun Zhang ◽  
Heng-Yue Xie ◽  
Wei-Ying Zhou ◽  
...  
Keyword(s):  
Cell Death ◽  
Chinese Medicine ◽  
Side Effects ◽  
Traditional Chinese Medicine ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Globin Gene ◽  
Terminal Differentiation ◽  
Point Of View ◽  
Hel Cells

Abstract Huangqi (Astragalus membranaceus), a traditional Chinese medicine, has been used to ameliorate side effects of cancer chemotherapy in China. However, little is known about its molecular mechanisms. Here we show that induction of K562 or HEL cells with 1.5 mg/ml of Huangqi (Hex) (Components extracted from Huangqi) for 3–5 d results in the expression of β-globin gene in both cell lines and leads to terminal differentiation. Moreover, the apoptosis in HEL cells can be induced by increasing concentration of Huangqi (Hex) to 4.5 mg/ml for 3–5 d. Upregulation of Apaf-1, caspase-3 and acetylcholinesterase (AChE) in HEL cells may play a crucial role in the process of apoptosis. The prospect of inducing expression of adult (β) globin gene and apoptosis selectively in cancer cells is obviously attractive from a therapeutic point of view.

scholarly journals Structure and Aggregation Mechanisms in Amyloids

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1195 ◽  
Author(s):  
Zaida L. Almeida ◽  
Rui M. M. Brito
Keyword(s):  
Molecular Species ◽  
Molecular Mechanisms ◽  
Amyloid Fibrils ◽  
Current Knowledge ◽  
Point Of View ◽  
Resonance Spectroscopy ◽  
Amyloid Formation ◽  
Amyloid Fibril Formation ◽  
Misfolding Diseases ◽  
Amyloid Cascade

The aggregation of a polypeptide chain into amyloid fibrils and their accumulation and deposition into insoluble plaques and intracellular inclusions is the hallmark of several misfolding diseases known as amyloidoses. Alzheimer′s, Parkinson′s and Huntington’s diseases are some of the approximately 50 amyloid diseases described to date. The identification and characterization of the molecular species critical for amyloid formation and disease development have been the focus of intense scrutiny. Methods such as X-ray and electron diffraction, solid-state nuclear magnetic resonance spectroscopy (ssNMR) and cryo-electron microscopy (cryo-EM) have been extensively used and they have contributed to shed a new light onto the structure of amyloid, revealing a multiplicity of polymorphic structures that generally fit the cross-β amyloid motif. The development of rational therapeutic approaches against these debilitating and increasingly frequent misfolding diseases requires a thorough understanding of the molecular mechanisms underlying the amyloid cascade. Here, we review the current knowledge on amyloid fibril formation for several proteins and peptides from a kinetic and thermodynamic point of view, the structure of the molecular species involved in the amyloidogenic process, and the origin of their cytotoxicity.

scholarly journals Clinical and Genetic Overview of Paroxysmal Movement Disorders and Episodic Ataxias

2020 ◽  
Vol 21 (10) ◽  
pp. 3603 ◽  
Author(s):  
Giacomo Garone ◽  
Alessandro Capuano ◽  
Lorena Travaglini ◽  
Federica Graziola ◽  
Fabrizia Stregapede ◽  
...  
Keyword(s):  
Movement Disorders ◽  
Molecular Mechanisms ◽  
Neurological Diseases ◽  
Single Gene ◽  
Point Of View ◽  
Whole Exome ◽  
Genetic Features ◽  
Neurogenetic Disorders ◽  
Next Generation Sequencing Ngs ◽  
Molecular Bases

Paroxysmal movement disorders (PMDs) are rare neurological diseases typically manifesting with intermittent attacks of abnormal involuntary movements. Two main categories of PMDs are recognized based on the phenomenology: Paroxysmal dyskinesias (PxDs) are characterized by transient episodes hyperkinetic movement disorders, while attacks of cerebellar dysfunction are the hallmark of episodic ataxias (EAs). From an etiological point of view, both primary (genetic) and secondary (acquired) causes of PMDs are known. Recognition and diagnosis of PMDs is based on personal and familial medical history, physical examination, detailed reconstruction of ictal phenomenology, neuroimaging, and genetic analysis. Neurophysiological or laboratory tests are reserved for selected cases. Genetic knowledge of PMDs has been largely incremented by the advent of next generation sequencing (NGS) methodologies. The wide number of genes involved in the pathogenesis of PMDs reflects a high complexity of molecular bases of neurotransmission in cerebellar and basal ganglia circuits. In consideration of the broad genetic and phenotypic heterogeneity, a NGS approach by targeted panel for movement disorders, clinical or whole exome sequencing should be preferred, whenever possible, to a single gene approach, in order to increase diagnostic rate. This review is focused on clinical and genetic features of PMDs with the aim to (1) help clinicians to recognize, diagnose and treat patients with PMDs as well as to (2) provide an overview of genes and molecular mechanisms underlying these intriguing neurogenetic disorders.

Apoptosis in human reproductive tissues: emerging concepts

1997 ◽  
Vol 6 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Masao Izawa ◽  
John Yeh
Keyword(s):  
Molecular Mechanisms ◽  
Point Of View ◽  
Human Reproduction ◽  
Diagnostic Tools ◽  
Important Process ◽  
Future Directions ◽  
Important Concept ◽  
Reproductive Tissues ◽  
Human Reproductive ◽  
Clinical Problems

In summary, apoptosis is an important concept in understanding many facets of human reproduction. Recent advances in the understanding of molecular mechanisms of apoptosis will allow us to understand this physiologically important process. How can the modulation of this process be applied to human reproduction? Studies to further understand the abnormalities of apoptosis, either too much or too little, may lead to a better understanding of the clinical problems in human reproduction.We summarize future directions towards further understanding the roles of apoptotic processes in human reproduction in Table 3. The diseases listed in Table 3 are problems which could be approached from the apoptosis point of view. With further study using this concept as the lens, new diagnostic tools or therapies may be developed for these problems.

scholarly journals STUDIES REGARDING DETERMINATION AND ESTABLISHING THE VALIDITY OF BOILED AND SMOKED MEAT PRODUCTS

2008 ◽  
Vol 65 (2) ◽  
Author(s):  
Adela Frigioiu Modoran ◽  
D. Frigioiu Modoran ◽  
I. Tofan
Keyword(s):  
Chemical Analysis ◽  
Food Additives ◽  
Meat Product ◽  
Meat Products ◽  
Modern Technology ◽  
Point Of View ◽  
Biological Value ◽  
Physical Chemical ◽  
Nutritional Characteristics

Underlining the validity problem can only be welcomed, given the conditions that in nowadays there doesnt exist a recipe without preservatives, antioxidants, colorants etc. Modern technology for meat products has a very important role in improving the quality of aliments, level of civilization and the prosperity of a country.In order to determine the validity of food products we have chosen as an example meat product as they have an equilibrated trophyne composition, a high biological value and special nutritional qualities.Using the cold air technologies in obtaining meat products ensures, together with the food additives, keeping of quality and nutritional characteristics of the final products.For this study we have chosen meat products from the group of boiled and smoked products: beer sausage. In the final we have analyzed the results of the experiment from the quality, microbiological and physical-chemical point of view. The quality exam referred to appreciate the aspect, color, taste, smell, consistency etc. The physical-chemical analysis determined humidity, salt, nitrates, Kreiss reaction and mg. NH3/100 g.

scholarly journals Más allá de la rehabilitación en una obra emblemática: monitorización de las cubiertas del hipódromo de la Zarzuela = Beyond the rehabilitation in an emblematic work: monitoring the decks of the Zarzuela racecourse

2018 ◽  
Vol 4 (2) ◽  
pp. 61 ◽  
Author(s):  
Isabel Martínez ◽  
Ángel Castillo
Keyword(s):  
Monitoring System ◽  
Continuous Measurement ◽  
Electrochemical Techniques ◽  
Chemical Processes ◽  
Point Of View ◽  
Measurement Monitoring ◽  
Long Period ◽  
Physical Chemical ◽  
Historical Heritage ◽  
Non Destructive

Resumen El hipódromo de la Zarzuela, declarado patrimonio histórico nacional, fue construido en Madrid en los años 40, y es una obra del Ingeniero Eduardo Torroja y los arquitectos Arniches y Domínguez. Las cubiertas de su estructura son consideradas un arte desde el punto de vista ingenieril. A pesar del perfecto y genial equilibrio físico y mecánico, se iniciaron procesos físicos y físico-químicos de deterioro en su composición debido al largo periodo de exposición de la estructura a la acción climática y al ataque de los agentes agresivos atmosféricos, entre los cuales se destaca como principal patología la corrosión por carbonatación de su armadura embebida. Dada la importancia de la obra desde el punto de vista artístico, histórico y de seguridad, las autoridades correspondientes decidieron su rehabilitación. En este proyecto de reparación se contempló la instalación de un sistema de monitorización de medidas continuas, mediante sensores electroquímicos pasivos, capaces de indicar el riesgo de corrosión en la armadura embebida de la estructura. De este modo, es posible controlar el comportamiento del material frente a la interacción con la acción atmosférica y prever la posible necesidad de intervenciones de mantenimiento, evitando el avance del deterioro con rapidez y garantías. La implementación de la monitorización requirió de una evaluación mediante técnicas electroquímicas no-destructivas del grado de deterioro previo a la intervención, para poder estudiar la evolución del comportamiento de la estructura después de la reparación. En el presente trabajo, se presentan los resultados obtenidos tanto en la evaluación electroquímica previa en las cubiertas del Hipódromo de la Zarzuela, como su posterior monitorización durante casi 10 años. Se presenta también la viabilidad del sistema de monitorización y su fiabilidad con el tiempo. Abstract La Zarzuela racecourse, declared a national historical heritage, was built in Madrid in the 1940s, and is a work by EngineerEduardo Torroja and the architects Arniches and Domínguez. The covers of its structure are considered an art from the engineeringpoint of view. Despite the perfect and ingenious physical and mechanical balance, physical and physical-chemical processes ofdeterioration in its composition were initiated due to the long period of exposure of the structure to climatic action and the attack ofaggressive atmospheric agents, among which the main pathology is the corrosion by carbonation of its embedded armor. Given theimportance of the work from the artistic, historical and security point of view, the corresponding authorities decided on itsrehabilitation. In this repair project, the installation of a continuous measurement monitoring system was contemplated, using passiveelectrochemical sensors, capable of indicating the risk of corrosion in the structure's embedded reinforcement. In this way, it is possibleto control the behavior of the material against the interaction with atmospheric action and to foresee the possible need for maintenanceinterventions, avoiding the advance of deterioration with speed and guarantees. The implementation of the monitoring required anevaluation by non-destructive electrochemical techniques of the degree of deterioration prior to the intervention, in order to study theevolution of the behavior of the structure after the repair. In the present work, the results obtained in the previous electrochemicalevaluation on the decks of the Hipódromo de la Zarzuela are presented, as well as their subsequent monitoring for almost 10 years.The viability of the monitoring system and its reliability over time are also presented.

scholarly journals OXIGÊNIO NO CONTEXTO DA COVID-19: O QUE SABEMOS SOBRE A MOLÉCULA QUE RESPIRAMOS E O PAPEL CENTRAL DA QUÍMICA

Química Nova ◽  
2021 ◽  
Author(s):  
Bruna Cerqueira ◽  
Bruna Silva ◽  
Rafael Campos ◽  
Lourenço Santana ◽  
Wilson Lopes ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Chemical Characterization ◽  
Point Of View ◽  
Oxygen Production ◽  
Oxygen Saturation Level ◽  
Light Emitting ◽  
Physical Chemical ◽  
Oxygen Cycle ◽  
Oxygen Concentrator

OXYGEN IN THE COVID-19 CONTEXT: WHAT WE KNOW ABOUT THE MOLECULE WE BREATHE AND THE CENTRAL ROLE OF CHEMISTRY. In this work, the role of chemistry in the coronavirus disease 2019 (COVID-19) pandemic is highlighted through the medical oxygen supply crises in Brazil, as an example of oxygen utility in health. Starting from oxygen chemical characterization, the oxygen cycle in nature is discussed to show how oxygen is formed through photosynthesis, followed by the description of the industrial oxygen production from atmospheric air, including physical-chemical aspects. The use of medical oxygen concentrator is presented and how this device works from the chemical point of view. Besides, the noninvasive and painless oximetry is described in terms of how oxygen saturation level in blood is measured using LED - light emitting diode.

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