scholarly journals ELECTRON MICROSCOPY OF LYSOSOME-RICH FRACTIONS FROM RAT THYMUS ISOLATED BY DENSITY-GRADIENT CENTRIFUGATION BEFORE AND AFTER WHOLE-BODY X-IRRADIATION

1962 ◽  
Vol 13 (2) ◽  
pp. 253-260 ◽  
Author(s):  
Y. E. Rahman
Keyword(s):  
Electron Microscopy ◽  
Acid Phosphatase ◽  
Cytochrome Oxidase ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Whole Body ◽  
Rat Tissues ◽  
Before And After ◽  
X Irradiation

Fractions from rat thymuses were isolated by sucrose density-gradient centrifugation, before and after 1000 r whole-body x-irradiation, and examined by electron microscopy. Cytochrome oxidase and acid phosphatase activities of these fractions were tested as well. Electron-opaque bodies with diameters ranging from 0.10 to 0.35 µ, with a mean of 0.25 µ, were found in fractions having high acid phosphatase activity, while the fractions rich in cytochrome oxidase consisted mostly of mitochondria. After irradiation, there was an increased ratio of dense bodies to mitochondria. These particles are considered to be lysosomes similar to those identified in other rat tissues. Their relationship to the mitochondria is discussed.

Uranyl Acetate and Rotary Shadowing to Increase the Contrast of Small Aggregated Virus Particles

1969 ◽  
Vol 27 ◽  
pp. 424-425
Author(s):  
Lee F. Ellis ◽  
Richard M. Van Frank ◽  
Walter J. Kleinschmidt
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Uranyl Acetate ◽  
Interferon Inducer ◽  
Virus Particles ◽  
Staining Methods ◽  
Rotary Shadowing

The extract from Penicillum stoliniferum, known as statolon, has been purified by density gradient centrifugation. These centrifuge fractions contained virus particles that are an interferon inducer in mice or in tissue culture. Highly purified preparations of these particles are difficult to enumerate by electron microscopy because of aggregation. Therefore a study of staining methods was undertaken.

Quantitative evaluation of polysomes and ribosomes by density gradient centrifugation and electron microscopy

1971 ◽  
Vol 43 (1) ◽  
pp. 71-79 ◽  
Author(s):  
R.E. Lecocq ◽  
F. Cantraine ◽  
E. Keyhani ◽  
A. Claude ◽  
C. Delcroix ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Density Gradient ◽  
Quantitative Evaluation ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation

scholarly journals Mucus glycoproteins from cystic fibrotic sputum. Macromolecular properties and structural ‘architecture’

1991 ◽  
Vol 276 (3) ◽  
pp. 667-675 ◽  
Author(s):  
D J Thornton ◽  
J K Sheehan ◽  
H Lindgren ◽  
I Carlstedt
Keyword(s):  
Electron Microscopy ◽  
Density Gradient ◽  
Proteinase Inhibitors ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Buoyant Density ◽  
Gel Chromatography ◽  
Guanidinium Chloride ◽  
Gel Phase ◽  
Mucus Glycoproteins

Mucus glycoproteins (mucins) were isolated from sputum of patients with cystic fibrosis (CF) after separation into sol and gel phases. The mucus gel was solubilized with gentle stirring in 6 M-guanidinium chloride supplemented with proteinase inhibitors, and purification of mucins was subsequently achieved by isopycnic density-gradient centrifugation in CsCl/guanidinium chloride. Density-gradient centrifugation also revealed a heterogeneity of the macromolecules, the pattern of which varied between individuals, and mucins from the gel phase was pooled as ‘heavy’ and ‘light’ fractions. Gel chromatography on Sepharose CL-2B showed that the heavy fraction contained a larger proportion of smaller species than the ‘light’ fraction and that the gel phase mucins were much larger than those from the sol. An apparently homogeneous high-Mr mucin population from one individual contained approx. 70% (w/w) carbohydrate, the major sugars being N-acetylglucosamine (17.8%), N-acetylgalactosamine (6.7%), galactose (20.7%), fucose (13.2%) and sialic acid (11.4%). These mucins had an S020.w of 47 S, and an Mr of 15 x 10(6) -20 x 10(6), and rate-zonal centrifugation revealed a polydisperse size distribution [range (5-30) x 10(6)] with a weight-average Mr of 17 x 10(6). The whole mucins were visualized with electron microscopy as linear and apparently flexible threads, disperse in size. Reduction produced subunits which were included on Sepharose CL-2B, and subsequent trypsin digestion yielded high-Mr glycopeptides which were further retarded. The size distributions and fragmentation patterns of mucin from two other CF patients were the same, as studied by gel chromatography, rate-zonal centrifugation and electron microscopy. We conclude that CF mucins are heterogeneous in both size and buoyant density and that the various populations, though differing in buoyant density, share the same architecture and macromolecular properties and are, in this respect, similar to mucins from normal respiratory secretions [Thornton, Davies, Kraayenbrink, Richardson, Sheehan & Carlstedt (1990) Biochem. J. 265, 179-186] and human cervical mucus [Carlstedt & Sheehan (1989) SEB Symp. XLIII 289-316].

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 effect of whole-body X-irradiation of guinea pigs on liver ribonucleic acid synthesis

1970 ◽  
Vol 116 (3) ◽  
pp. 503-514 ◽  
Author(s):  
E. J. Hidvégi ◽  
Elisabeth Bölöni ◽  
J. Holland ◽  
F. Antoni ◽  
V. Várterész
Keyword(s):  
Orotic Acid ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Polymerase Activity ◽  
Whole Body ◽  
Sucrose Density Gradient Centrifugation ◽  
Polyuridylic Acid ◽  
X Irradiation ◽  
Rna Polymerase Activity

1. Liver RNA synthesis was studied within 24h after whole-body X-irradiation of guinea pigs that had been starved for 22–24h. 2. Microsomal RNA was labelled in vivo for 3h with [14C]orotic acid and the isolated labelled RNA was fractionated by sucrose-density-gradient centrifugation. Incorporation was 50–100% higher between 3 and 12h after 2000rd X-irradiation and at 22h was not elevated any further. Whole nuclear RNA was labelled with [14C]orotic acid for 15min. At 5h after irradiation the incorporation showed a 50–100% increase. Incorporation increased in all types of RNA studied. 3. The RNA phosphorus/DNA phosphorus ratio of whole liver gradually increased after X-irradiation. Maximal increase was found between 24 and 36h, which corresponds to a value about 40% above that of the starved control. The RNA phosphorus content of isolated ribonucleoproteins obtained from various cell fractions of the liver was similarly increased after X-irradiation. 4. Liver microsomes were obtained from X-irradiated and control animals. Microsomes were incubated in vitro with [14C]phenylalanine in the presence and absence of polyuridylic acid. After the incubation the microsomes were fractionated by sucrose-density-gradient centrifugation. The polyuridylic acid enhancement was twice as great in the microsomes of the control preparation as in the irradiated one. The experiment demonstrated a higher saturation of microsomes by endogenous messenger after X-irradiation. 5. RNA polymerase activity of the purified nuclear preparation was assayed. The activity of the Mg2+-dependent RNA polymerase activity was 50 and 200% respectively above the control values at 6 and 9h after X-irradiation. 6. Animals were treated with actinomycin D shortly before X-irradiation. This treatment abolished the radiation-induced enrichment of polyribosomes and the increase of protein-synthesizing activity. The effect of X-irradiation on the transcription of the genetic code of the liver is discussed.

scholarly journals IMPACT OF PREPARATION USING CONVENTIONAL AND MODIFIED DENSITY GRADIENT CENTRIFUGATION METHODS ON SPERM CONCENTRATION, MOTILITY AND NUMBER OF NORMAL MOTILE SPERM RECOVERY (NMSR)

2017 ◽  
Vol 53 (3) ◽  
pp. 196
Author(s):  
Rina Yudiwati ◽  
MPBD Pramesti ◽  
Agustinus Agustinus ◽  
E Pradana ◽  
Bambang Purwanto
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sperm Concentration ◽  
Control Group ◽  
Control Group Design ◽  
Advanced Technique ◽  
Sperm Analysis ◽  
Before And After ◽  
Preparation Techniques

Some preparation techniques, either conventional or advanced, have been provided. Advanced technique may overcome the limitations of conventional techniques. Recently, not all fertility clinics in Indonesia are able to provide advanced preparation techniques. Some techniques require expensive equipments and can only be used for intracytoplasmic sperm injection (ICSI). Some fertility clinics use a modified procedure, namely the combination of density gradient centrifugation with a swim-up method for the preparation of the sperm to be used in ART. This study aimed to determine whether the modified density gradient centrifugation, which is density gradient centrifugation followed by a swim-up, is able to yield better results than conventional density gradient centrifugation. This study was a laboratory experimental pre and pos-test control group design. Population was all adult men aged 21-40 years old and the sampling unit was the man donor’s semen which fulfilled inclusion criterias, collected during the periode of the study. Sample size was eight. Sperm analysis were done before and after preparation in conventional and modified group. Descriptive comparation analysis have been used. This study obtained NMSR 7.9+5.5 million/ejaculate and recovery rate (RR) 27.66+11.8 %. RR was lower compared to RR obtained conventional DGC method. RR might be lower because in modified DGC samples undergo two steps selection while conventional DGC only one step selection. But conventional DGC samples should be centrifuged twice, therefore sperms might experience more trauma. Lower RR sperm does not exclude the possibility to be used for ART, because still within the required number for all TRBs. In conclusion, modified DGC preparation method obtained lower NMSR and RR, nevertheless harvested sperms can still be used in all kind of ART.

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