scholarly journals STUDY OF MITOCHONDRIA IN RAT LIVER

1962 ◽  
Vol 15 (3) ◽  
pp. 489-501 ◽  
Author(s):  
Gunter F. Bahr ◽  
Elmar Zeitler
Keyword(s):  
Electron Microscopy ◽  
Rat Liver ◽  
Linear Growth ◽  
Mitochondrial Fraction ◽  
The Other ◽  
Quantitative Electron Microscopy ◽  
Normal Rat ◽  
Log Normal ◽  
Log Normal Distribution ◽  
Particle Weight

The electron microscope has been used to determine the weight distribution of isolated subcellular particles from normal rat liver. The following results are reported: (1) There exist at least two well defined weight populations of subcellular particles; their respective median weights are 1.3 x 10-14 and 11 x 10-14 gm. The lighter fraction is considered to consist of lysosomes, the heavier of mitochondria. (2) The mitochondrial fraction shows a log-normal distribution of the particle weight. (3) By the introduction of morphologic criteria, the mitochondrial fraction is divided into two groups, one consisting of a spherical, the other of an oblong type of particle. The data found support the following concepts: (a) Mitochondria increase their weight from a certain size up by linear growth. (b) Mitochondria divide. The division is not necessarily symmetric; in all cases, however, one part of the division product is a spherical particle. It is felt that these results constitute a valuable demonstration of the general capabilities of quantitative electron microscopy and may stimulate many other useful applications of this technique in cytology, bacteriology, and virology.

scholarly journals Extraction of an Erythropoietin-Producing Factor from a Particulate Fraction of Rat Kidney

Blood ◽  
1966 ◽  
Vol 28 (3) ◽  
pp. 330-343 ◽  
Author(s):  
JOSEPH F. CONTRERA ◽  
ALBERT S. GORDON ◽  
ARTHUR H. WEINTRAUB
Keyword(s):  
Rat Kidney ◽  
Deae Cellulose ◽  
Mitochondrial Fraction ◽  
Normal Serum ◽  
The Other ◽  
Step Method ◽  
Renal Vasculature ◽  
Rat Serum ◽  
Normal Rat ◽  
Strong Resemblance

Abstract 1. A two-step method for the extraction of erythropoietin from hypoxic kidneys has been developed which allows residual plasma erythropoietin in renal vasculature to be separated from that of intracellular origin. 2. Renal extracts have been purified by DEAE cellulose chromatography and found to contain 2 major erythropoietically active fractions. One bears strong resemblance to plasma erythropoietin. The other component is unique in that it has practically no erythropoietic-stimulating activity unless previously incubated with normal rat serum. This activation phenomenon is used to identify this kidney component as the renal erythropoietic factor (REF). The REF has the capacity to produce erythropoietin or become erythropoietically active when incubated with normal rat serum. 3. Differential centrifugation technics revealed that the REF is confined to particles present in the light mitochondrial fraction of kidney. 4. Extracts of the light mitochondrial fraction of kidneys from normal rats produced significant amounts of erythropoietin when incubated with normal serum. The quantity found, however, was less than that evoked by similar extracts of kidneys from hypoxic rats. 5. The product of the incubation extracts of the renal light mitochondrial fraction with normal rat serum showed the same log dose/response regression as sheep plasma erythropoietin standard. 6. It is hypothesized that either (a) the REF is a precursor of erythropoietin which must be complexed with a carrier present in normal serum in order to become physiologically active, or (b) the renal factor is an enzyme which produces erythropoietin by its action on a particular serum protein.

scholarly journals Settling Analyses and Investigations of Clayey Sediments to Storage in Geotubes

2021 ◽  
Vol 13 (15) ◽  
pp. 8475
Author(s):  
Marco Perna ◽  
Annamaria De Vincenzo ◽  
Giuseppe Di Nunzio ◽  
Bruno Molino ◽  
Luigi Ambrosone
Keyword(s):  
Physical Properties ◽  
Unit Area ◽  
Kinetic Constant ◽  
Average Diameter ◽  
The Other ◽  
Coarse Grained ◽  
Solid Concentration ◽  
Log Normal ◽  
Log Normal Distribution ◽  
Two Parameter

Understanding the sedimentation behaviour and chemical–physical properties of clay sediments is crucial in planning their storage in geotubes. Analysis of the sedimentation curves of the solids taken from the artificial reservoir of the Camastra reveal that a two-parameter curve identifies all the sedimentation profiles. One parameter depends on the type of settling material, and the other is the lifetime of the process. Using the solid concentration per unit area, the lifetime is converted into a true kinetic constant. These parameters uniquely identify the sedimentation profile to be used in the management of dredging using geotubes. Furthermore, the resulting particles after the decantation of the coarse-grained solids are dispersed according to a log-normal distribution with an average diameter between 250 and 500 nm. The low ζ-potential of the particles dispersed in the supernatant indicates that they can either aggregate or adsorb to the geotube tissue, slowing or blocking the dredging operations.

Isolation of the 67Gallium Accumulating Fraction in Normal Rat Liver

1974 ◽  
Vol 13 (01) ◽  
pp. 72-84
Author(s):  
K. Hierholzer ◽  
K. zum Winkel ◽  
U. Haubold ◽  
E. Aulbert
Keyword(s):  
Electron Microscopy ◽  
Density Gradient ◽  
Intravenous Injection ◽  
Rat Liver ◽  
Soluble Fraction ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Differential Centrifugation ◽  
Normal Rat

SummarySubcellular 67Gallium distribution was investigated in normal rat liver after intravenous injection. By differential centrifugation and density gradient centrifugation 67Gallium accumulating bodies were isolated and identified as lysosomes by enzyme determination and electron microscopy. 67Gallium enrichment in this fraction was 23-fold. Using the isolated 67Gallium accumulating lysosomes the binding state of the isotope inside the lysosomes was studied. 67Gallium was found to be associated with the soluble fraction of lysosomes.

scholarly journals The aerosol distribution in Europe derived with the Community Multiscale Air Quality (CMAQ) model: comparison to near surface in situ and sunphotometer measurements

2008 ◽  
Vol 8 (17) ◽  
pp. 5077-5097 ◽  
Author(s):  
V. Matthias
Keyword(s):  
Distribution Function ◽  
Air Quality ◽  
Normal Distribution ◽  
The Other ◽  
Near Surface ◽  
Aerosol Mass ◽  
Aerosol Distribution ◽  
Log Normal ◽  
Log Normal Distribution ◽  
Distribution In Europe

Abstract. The aerosol distribution in Europe was simulated with the Community Multiscale Air Quality (CMAQ) model system version 4.5 for the years 2000 and 2001. The results were compared with daily averages of PM10 measurements taken in the framework of EMEP and with aerosol optical depth (AOD) values measured within AERONET. The modelled total aerosol mass is typically about 30–60% lower than the corresponding measurements. However a comparison of the chemical composition of the aerosol revealed a considerably better agreement between the modelled and the measured aerosol components for ammonium, nitrate and sulfate, which are on average only 15–20% underestimated. Sligthly worse agreement was determined for sea salt, that was only avaliable at two sites. The largest discrepancies result from the aerosol mass which was not chemically specified by the measurements. The agreement between measurements and model is better in winter than in summer. The modelled organic aerosol mass is higher in summer than in winter but it is significantly underestimated by the model. This could be one of the main reasons for the discrepancies between measurements and model results. The other is that primary coarse particles are underestimated in the emissions. The probability distribution function of the PM10 measurements follows a log-normal distribution at most sites. The model is only able to reproduce this distribution function at non-coastal low altitude stations. The AOD derived from the model results is 20–70% lower than the values observed within AERONET. This is mainly attributed to the missing aerosol mass in the model. The day-to-day variability of the AOD and the log-normal distribution functions are quite well reproduced by the model. The seasonality on the other hand is underestimated by the model results because better agreement is achieved in winter.

scholarly journals The evaluation of fabrics in relation to their use as protective garments in nursing and surgery. II. Dispersal of skin organisms in a test chamber

1978 ◽  
Vol 81 (3) ◽  
pp. 453-470 ◽  
Author(s):  
O. M. Lidwell ◽  
C. A. Mackintosh ◽  
A. G. Towers
Keyword(s):  
High Surface ◽  
Test Chamber ◽  
The Other ◽  
Unidirectional Flow ◽  
Electrostatic Charges ◽  
Clean Air ◽  
The Mean ◽  
Experimental Values ◽  
Log Normal ◽  
Log Normal Distribution

SummaryThe effectiveness of a representative range of fabrics in restricting dispersal through them of dry skin-borne bacteria has been examined. The fabrics were tested made up into trousers which were worn by volunteers during standardized exercise in a test chamber operated within a unidirectional flow clean-air room. Under these conditions, with careful attention to sealing at ankles and waist, it was possible to estimate penetration as low as 0·3%. Penetrations as low as 1% were observed with some synthetic fabrics. These had a relatively high surface resistivity and developed significant electrostatic charges.When the observed values for penetration were compared with the results of a series of measurements and tests made on the fabrics it was clear that the correlation between these values and the other results was in every case very close for all the five woven cotton or cotton terylene fabrics but that no measurement or test was capable of predicting the behaviour of all the other materials in dispersal experiments. The inherent variability of dispersal experiments seems to be very great. With a standard deviation of the approximately log-normal distribution of the experimental values as high as about 2 times the mean, it is necessary to carry out as many as 20 replicate experiments in order to differentiate with certainty between garments with a two-fold difference in penetration.

scholarly journals Incorporation of oxygen-18 into the 25-position of cholecalciferol by hepatic cholecalciferol 25-hydroxylase

1978 ◽  
Vol 175 (2) ◽  
pp. 479-482 ◽  
Author(s):  
T C Madhok ◽  
H K Schnoes ◽  
H F DeLuca
Keyword(s):  
Rat Liver ◽  
Mitochondrial Fraction ◽  
The Other ◽  
Mixed Function Oxidase ◽  
25 Hydroxycholecalciferol

The oxygen enzymically inserted as a hydroxy function by rat liver post-mitochondrial fraction into the 25-position of cholecalciferol to giver 25-hydroxycholecaliferol is derived exclusively from molecular O2. Therefore like the other two cholecalciferol hydroxylases, i.e. 25-hydroxycholecalciferol 1alpha-hydroxylase and 25-hydroxycholecalciferol 24-hydroxylase, the cholecalciferol 25-hydroxylase is also a mono-oxygenase (‘mixed-function oxidase’).

Development of 200 kV Scanning-Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 410-411
Author(s):  
H. Koike ◽  
S. Sakurai ◽  
K. Ueno ◽  
M. Watanabe
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
The Other ◽  
Morphological Observation ◽  
Magnetic Domains ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Backscattered Electron ◽  
Increasing Demand

In recent years, there has been increasing demand for higher voltage SEMs, in the field of surface observation, especially that of magnetic domains, dislocations, and electron channeling patterns by backscattered electron microscopy. On the other hand, the resolution of the CTEM has now reached 1 ∼ 2Å, and several reports have recently been made on the observation of atom images, indicating that the ultimate goal of morphological observation has beem nearly achieved.

Effects of Hypophysectomy on the Fine Structure of Rat Liver Cells

1967 ◽  
Vol 25 ◽  
pp. 156-157
Author(s):  
Robert R. Cardell
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Rat Liver ◽  
Liver Cell ◽  
Anterior Pituitary ◽  
Liver Cells ◽  
Biochemical Studies ◽  
Liver Functions ◽  
Rat Liver Cells ◽  
And Control

Hypophysectomy of the rat renders this animal deficient in the hormones of the anterior pituitary gland, thus causing many primary and secondary hormonal effects on basic liver functions. Biochemical studies of these alterations in the rat liver cell are quite extensive; however, relatively few morphological observations on such cells have been recorded. Because the available biochemical information was derived mostly from disrupted and fractionated liver cells, it seemed desirable to examine the problem with the techniques of electron microscopy in order to see what changes are apparent in the intact liver cell after hypophysectomy. Accordingly, liver cells from rats which had been hypophysectomized 5-120 days before sacrifice were studied. Sham-operated rats served as controls and both hypophysectomized and control rats were fasted 15 hours before sacrifice.

Comparative strengths and weaknesses of peroxidase and colloidal gold in pre- and post-embedding immunolabeling techniques

1987 ◽  
Vol 45 ◽  
pp. 1002-1005
Author(s):  
D. R. Abrahamson ◽  
P. L. St.John ◽  
E. W. Perry
Keyword(s):  
Electron Microscopy ◽  
Horseradish Peroxidase ◽  
Light Microscopy ◽  
Colloidal Gold ◽  
Light Microscope ◽  
Ultrastructural Localization ◽  
The Other ◽  
Quantitative Studies ◽  
Dense Suspension ◽  
Antigen Localization

Antibodies coupled to tracers for electron microscopy have been instrumental in the ultrastructural localization of antigens within cells and tissues. Among the most popular tracers are horseradish peroxidase (HRP), an enzyme that yields an osmiophilic reaction product, and colloidal gold, an electron dense suspension of particles. Some advantages of IgG-HRP conjugates are that they are readily synthesized, relatively small, and the immunolabeling obtained in a given experiment can be evaluated in the light microscope. In contrast, colloidal gold conjugates are available in different size ranges and multiple labeling as well as quantitative studies can therefore be undertaken through particle counting. On the other hand, gold conjugates are generally larger than those of HRP but usually can not be visualized with light microscopy. Concern has been raised, however, that HRP reaction product, which is exquisitely sensitive when generated properly, may in some cases distribute to sites distant from the original binding of the conjugate and therefore result in spurious antigen localization.

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