scholarly journals Cytophotometric analyses of myocardial RNA in rats exposed to altitude hypoxia.

1978 ◽  
Vol 26 (6) ◽  
pp. 459-467 ◽  
Author(s):  
A J Stere ◽  
N W Brister ◽  
A Anthony
Keyword(s):  
Coefficient Of Variation ◽  
Rna Synthesis ◽  
Prolonged Exposure ◽  
Progressive Increase ◽  
High Variability ◽  
Vascular Responses ◽  
Hypoxia Exposure ◽  
Azure B ◽  
Exposure Interval ◽  
Rna Levels

Analytical cytophotometry of azure B-stained heart sections was employed to investigate the pattern of myocardial ribonucleic acid (RNA) alterations in rats exposed to acute (1-2 days) and prolonged periods (1-8 weeks) of hypoxia exposure (380 torr). Data support the existence of a slight transient drop in myocardial RNA on day one of exposure followed by a restoration to levels slightly elevated over controls during a 1- to 8-week exposure interval. Because of the high variability in RNA levels among myocytes (coefficient of variation, ca 40%), a shift in the proportion of low and high RNA containing segments of the myocyte population proved to be a more sensitive indicator of suppression or augmentation of RNA synthesis than the use of average RNA levels of the cell population analyzed. Microscopic analyses revealed the presence of compensatory vascular responses which could be effective in ameliorating the extent of tissue hypoxemia, i.e., capillary vasodilation on day 1 with a progressive increase in vascularization with prolonged exposure.

Progressive Increase in Platelet Activation With Smoke Exposure: Human Subject and In-Vitro Studies

2007 ◽  
Author(s):  
Gaurav Girdhar ◽  
Sulan Xu ◽  
Jolyon Jesty ◽  
Danny Bluestein
Keyword(s):  
Cigarette Smoke ◽  
Platelet Activation ◽  
Human Subject ◽  
Prolonged Exposure ◽  
Human Subjects ◽  
Progressive Increase ◽  
In Vitro Studies ◽  
Protective Effects ◽  
Shs Exposure

Second hand cigarette smoke (SHS) is one of the major risk factors for cardiovascular disease (CVD) and has been shown to substantiate platelet activation and aggregation in several studies [1, 2]. Most of these studies, under chronic or acute exposure conditions or over prolonged exposure, do not represent the initiation of a disease state or hematological damage under normal levels of cigarette smoke. These above studies of platelet activation with SHS together with our previous in-vitro studies demonstrating cardio-protective effects of nicotine [3], have motivated the present investigation of physiological levels of SHS exposure on human subjects and within an in-vitro endothelial cell-platelet system, with cigarettes (or smoke extracts) of varying nicotine content to confirm analogous cardio-protective effects of nicotine.

Reliability analysis of stabilisation pond systems

2007 ◽  
Vol 55 (11) ◽  
pp. 127-134 ◽  
Author(s):  
S.M.A.C. Oliveira ◽  
M. von Sperling
Keyword(s):  
Reliability Analysis ◽  
Coefficient Of Variation ◽  
High Variability ◽  
Full Scale ◽  
Operating Conditions ◽  
Effluent Quality ◽  
Standard Values ◽  
Expected Compliance

This article presents a reliability analysis of 116 full-scale pond systems in Brazil, comprising 73 primary facultative ponds and 43 anaerobic–facultative pond systems. A methodology developed by Niku et al. (1979) is used for the determination of the coefficients of reliability, in terms of the compliance of effluent BOD, COD, TSS and FC to discharge standards or effluent quality targets. The design concentrations necessary to meet the prevailing discharge standards and the expected compliance percentages have been calculated from the coefficients of reliability obtained. The results showed that few units, under the observed operating conditions, would be able to present reliable performances in terms of compliance with the analyzed standards. For the four constituents (BOD, COD, TSS and FC) and both systems (facultative ponds and anaerobic-facultative systems), the variability of the effluent quality was very large, leading to a high variability of the coefficient of variation (CV) and the coefficient of reliability (COR). The effluent quality from the facultative ponds showed a larger distance to both the desired values and the discharge standard values, compared with the anaerobic–facultative systems.

scholarly journals Inferences on RNA synthesis rates during mitosis from flow cytofluorimetric RNA histograms.

1978 ◽  
Vol 26 (9) ◽  
pp. 691-695 ◽  
Author(s):  
J V Watson ◽  
S H Chambers
Keyword(s):  
Acridine Orange ◽  
Rna Synthesis ◽  
Acridine Orange Staining ◽  
Rna Content ◽  
Mitotic Cells ◽  
Rna Levels

Flow cytofluorimetric techniques with acridine orange staining have been used to study RNA levels of cells during and immediately after mitosis. It can be inferred from the histogram data that, of the mitotic cells, those in telophase have the highest RNA content, and that the rate of synthesis increases rapidly between anaphase and telophase. These inferences correlate with results obtained from parallel labeled precursor studies.

scholarly journals VARIABILITY OF SEASONAL AND ANNUAL RUNOFF IN NORWAY

1972 ◽  
Vol 3 (2) ◽  
pp. 72-79 ◽  
Author(s):  
ARNE TOLLAN
Keyword(s):  
Coefficient Of Variation ◽  
Catchment Area ◽  
Annual Runoff ◽  
High Variability ◽  
Convective Precipitation ◽  
Regional Pattern ◽  
Precipitation Regimes ◽  
Runoff Regime ◽  
Monthly Runoff ◽  
Eastern Norway

A preliminary map of variability of annual runoff in Norway has been prepared based on estimates of the coefficient of variation cv for 56 non-regulated discharge stations having more than 35 years of continuous observations. The regional pattern of cv reflects the altitude and possibly also the different precipitation regimes of Norway; low variability characterizes the wet western part of the country where frontal precipitation dominates, and relatively high variability typifies the drier South-Eastern Norway where considerable amounts of convective precipitation are common. cv for annual runoff is slightly affected by catchment area. Variability of monthly runoff also shows a regional pattern which is interpreted in terms of runoff regime characteristics.

scholarly journals Metabolic labelling of RNA uncovers the contribution of transcription and decay rates on hypoxia-induced changes in RNA levels

2019 ◽  
Author(s):  
Maria Tiana ◽  
Clara Galiana ◽  
Miguel Ángel Fernández-Moreno ◽  
Benilde Jimenez ◽  
Luis del Peso
Keyword(s):  
Rna Synthesis ◽  
Environmental Changes ◽  
Hypoxia Inducible Factor ◽  
Rna Degradation ◽  
Decay Rates ◽  
Specific Gene ◽  
Metabolic Labeling ◽  
Low Oxygen ◽  
Degradation Rates ◽  
Rna Levels

ABSTRACTCells adapt to environmental changes, including fluctuations in oxygen levels, through the induction of specific gene expression programs. However, most transcriptomic studies do not distinguish the relative contribution of transcription, RNA processing and RNA degradation processes to cellular homeostasis. Here we used metabolic labeling followed by massive parallel sequencing of newly transcribed and preexisting RNA fractions to simultaneously analyze RNA synthesis and decay in primary endothelial cells exposed to low oxygen tension. We found that the changes in transcription rates induced by hypoxia are the major determinant of RNA levels. However, degradation rates also had a significant contribution, accounting for 24% of the observed variability in total mRNA. In addition, our results indicated that hypoxia led to a reduction of the overall mRNA stability from a median half-life in normoxia of 8.7 hours, to 5.7 hours in hypoxia. Analysis of RNA content per cell confirmed a decrease of both mRNA and total RNA in hypoxic samples and that this effect was mimicked by forced activation of the Hypoxia Inducible Factor pathway and prevented by its interference. In summary, our study provides a quantitative analysis of the contribution of RNA synthesis and stability to the transcriptional response to hypoxia and uncovers an unexpected effect on the latter.

The Effect of Actinomycin D in Vivo Upon Peripheral Nucleoli and Other Nuclear Organelles in Oocytes of Triturus Cristatus

1972 ◽  
Vol 10 (3) ◽  
pp. 833-855
Author(s):  
M. H. L. SNOW
Keyword(s):  
Phase Contrast ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Triturus Cristatus ◽  
Granular Component ◽  
Azure B ◽  
Final Maturation ◽  
Ribosomal Precursor ◽  
20 Nm

Exposure of the ovaries of Triturus cristatus to actinomycin D at a concentration of 100 µg/ml causes characteristic changes in the peripheral nucleoli and other nuclear organelles in oocytes of 0.6-1.1 mm diameter. Viewed with the light microscope untreated oocytes contain nucleoli that stain uniformly with a variety of dyes. They also appear homogeneous tmder phase-contrast optics. After 2 or 4 h of in vivo incubation with actinomycin D, oocyte sections stained with Haidenhain's haematoxylin or viewed under phase-contrast optics show nucleoli composed of 2 regions. The more heavily stained or contrasted zone is crescent-shaped and directed away from the nuclear membrane. Neither sections stained with azure B bromide nor gallocyanin chrome alum show this feature. Ribonuclease digestion does not eliminate or alter it. Autoradiography with [3H]uridine indicates that all recently synthesized RNA is lost from the nucleolus during actinornycin D treatment. The zonation is not therefore a reflexion of RNA distribution. During recovery from actinomycin D poisoning there is a reduction in the degree of zonation shown by nucleoli which re-establish a normal appearance some 48 h after treatment. Electron microscopy of peripheral nucleoli in oocytes sampled during this treatment indicates that the zonation is not associated with reorganization of ultrastructural components. During incubation with actinomycin D the coarse granules (20 nm diameter) are completely lost from the nucleolus. There is associated shrinkage of the nucleolus which after treatment is found to consist entirely of fibrils (5 nm thick) and small granules. The reappearance of the coarse granules during recovery is completed in about 48 h. It is thought that the loss of the granular component during treatment represents the movement of the 30-S precursor and the 18-s ribosomal unit from the nucleolus. Some 20-30 µm inside the nucleus of untreated oocytes is a region containing many spheroidal bodies, less than 1.0 µm diameter. They have been termed micronucleoli and consist of granules 2.5-5 nm in diameter and fibrils of similar thickness. Actinomycin D treatment causes these components to segregate and eventually (within 24 h of treatment) the granular component is extruded. This component reappears during the second day after treatment. It is postulated that these micronucleoli represent the sites at which the 30-S ribosomal precursor undergoes its final maturation. The segregation of components induced by actinomycin D is probably the morphological manifestation of an abnormal metamorphosis of this precursor. Treatment with actinomycin D also induces the immediate formation within the nucleus of crystalline bodies composed of lamellae 16 nm wide, 4 nm thick and with a centre-to-centre spacing of 8-10 nm. They are not present 24 h after treatment. They are thought to represent a protein fraction normally associated with periods of intense RNA synthesis.

scholarly journals REFORMATION OF NUCLEOLUS-LIKE BODIES IN THE ABSENCE OF POSTMITOTIC RNA SYNTHESIS

1971 ◽  
Vol 48 (3) ◽  
pp. 443-454 ◽  
Author(s):  
A. R. Stevens ◽  
D. M. Prescott
Keyword(s):  
Rna Synthesis ◽  
Actinomycin D ◽  
Amoeba Proteus ◽  
Nucleolar Protein ◽  
Fibrillar Material ◽  
Azure B ◽  
Late Anaphase ◽  
High Concentrations

The dependence of nucleolar reformation on RNA synthesis that resumes in late anaphase or early telophase has been investigated in synchronously dividing Amoeba proteus. RNA synthesis was completely inhibited throughout all stages of mitosis and the early hours of interphase with high concentrations of actinomycin D. In such cells, nucleolus-like bodies that bind azure B and pyronin were apparent in the reformed nuclei. The bodies appear as dense, fibrous masses with loosely associated, finely fibrillar material. There are no characteristic granular regions in the reformed structures. It is suggested that the bodies probably represent mainly nucleolar protein and residual RNA which can bring about the reorganization of nucleoli in the absence of postmitotic RNA synthesis.

scholarly journals Reverse Transcription-Competitive Multiplex PCR Improves Quantification of mRNA in Clinical Samples—Application to the Low Abundance CFTR mRNA

1999 ◽  
Vol 45 (5) ◽  
pp. 619-624 ◽  
Author(s):  
Stefan M Loitsch ◽  
Stefan Kippenberger ◽  
Nurlan Dauletbaev ◽  
Thomas OF Wagner ◽  
Joachim Bargon
Keyword(s):  
Cystic Fibrosis ◽  
Gene Therapy ◽  
Multiplex Pcr ◽  
Reverse Transcription ◽  
Coefficient Of Variation ◽  
High Variability ◽  
Clinical Samples ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Cystic Fibrosis Transmembrane

Abstract Background: To monitor gene therapy, we wished to quantify cystic fibrosis transmembrane conductance regulator (CFTR) mRNA. We developed a PCR-based method to measure CFTR mRNA in clinical samples. Methods: Expression was determined by reverse transcription-competitive multiplex PCR (RCMP) for CFTR and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcripts, and for serial dilutions of two internal cDNA standards consisting of CFTR and GAPDH mutants containing short deletions. The RCMP used simultaneous amplification of the gene of interest with a reporter gene in one reaction tube. The expression of CFTR was calculated with reference to the amount of GAPDH to correct for variations in initial RNA loading. Results: Amplification of cDNAs derived from different amounts of RNA (1–4 μg) gave similar GAPDH/CFTR ratios, with a coefficient of variation (CV) below 7.5%. RCMP was applied on nasal and bronchial brushings and shows a high variability of CFTR expression in non-cystic fibrosis donors. Conclusion: This method is precise and reproducible and advantageous for use with limited amounts of tissue, such as from biopsies or from nasal or bronchial brushings.

scholarly journals Ordinary Least Products Regression: A Robust Statistical Tool for Assessing Agreement Between Measures Attended by High Variability

2020 ◽  
Author(s):  
Marcus Nascimento-Ferreira ◽  
Augusto De Moraes ◽  
Heraclito Carvalho
Keyword(s):  
Confidence Intervals ◽  
Random Error ◽  
Coefficient Of Variation ◽  
Statistical Approach ◽  
High Variability ◽  
Statistical Tool ◽  
Bland Altman Method ◽  
Behavioral Variables ◽  
Two Measures ◽  
Fixed Bias

Abstract Background: Agreement (and disagreement) assessments are essential steps in the evaluation of new and existing methods. We aimed to provide a statistical approach to assess systematic disagreement between two measures/methods when both are attended by random error and high variability. Methods: We applied ordinary least products (OLP) regression and the Bland-Altman method in six simulated pairs of samples. In OLP regression, fixed bias defined if 95% confidence intervals (CIs) of the intercept did not include 0. Proportional bias was defined if 95% CIs of the slope did not include 1. As a comparator, we assessed fixed and proportional bias by the Bland-Altman method. Results: We found divergence between studied statistical method outcomes only for measures with low variability (coefficient of variation, CV < 25,0%). Conclusion: OLP regression is a simple and powerful tool for detecting systematic disagreement when the measures are attended by high variability, as well as behavioral variables.

Morphological and morphometric parameters of Clematis flammula on the Protected Areas of the Southern Coast of Crimea

2020 ◽  
pp. 116-123
Author(s):  
Ya. A. Perminova ◽  
O. N. Reznikov ◽  
N. A. Bagrikova
Keyword(s):  
Protected Areas ◽  
Coefficient Of Variation ◽  
Seed Weight ◽  
High Variability ◽  
Morphometric Parameters ◽  
Southern Coast ◽  
Leaf Petiole ◽  
Qualitative And Quantitative ◽  
Quantitative Parameters

The paper presents the results of some of the qualitative and quantitative parameters of Clematis flammula plants study. The plants have been naturalized in different phytocenotic conditions of the Southern Coast of Crimea. It has been found that in the studied plants most of the parameters of leaves and flowers are characterized by an average variability (10 <Cv <30). Plants also differ in the shape and dissection of the leaves. Low coefficient of variation (Cv, up to 10%) of a seed weight indicates an insignificant variability of this parameter.The parameter such as the length of the leaf petiole (Cv, 43-59%) is distinguished by a high variability.

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