Micron (1969)Pub Date : 1982-01-01DOI: 10.1016/0047-7206(82)90082-6
James R. Harris
{"title":"Some negative staining electron microscopic and biochemical studies on apoferritin and its oligomers","authors":"James R. Harris","doi":"10.1016/0047-7206(82)90082-6","DOIUrl":"10.1016/0047-7206(82)90082-6","url":null,"abstract":"<div><p>Native horse spleen apoferritin, which is a mixture containing predominantly the 17S monomer with gradually decreasing amounts of dimer, trimer, tetramer, pentamer and higher oligomers, has been studied by polyacrylamide gel electrophoresis in non-dissociating systems, analytical ultracentrifugation and negative staining electron microscopy. The apoferritin monomer has been purified by preparative polyacrylamide gel electrophoresis and gel slicing of analytical polyacrylamide gels. From an oligomer enriched fraction obtained by Sepharose 6B gel filtration chromatography, the dimer and trimer have been successfully purified and a tetramer + higher oligomer fraction obtained by gel slicing of analytical polyacrylamide gels. The stability of the separated fractions during electrophoresis and negative staining is clearly demonstrated. The oligomer fractions can, however, be readily dissociated into monomer and lower oligomers by subjecting them to ultrasonication, the degree of dissociation being time dependent at a fixed ultrasonication intensity. The number of possible conformations for the higher oligomers clearly increases with the number of monomers present in the group, resulting in varied electron optical images of the apparently randomly linked monomers. The production of an increased amount of inter-molecular cross-linking has been achieved by treatment with low concentrations of glutaraldehyde (up to 0.05%). This treatment produced a diminution of the monomer band on polyacrylamide electropherograms, with an increased amount of higher oligomers. Oligomers above the pentamer are not clearly revealed by the electrophoretic systems used, owing to their inability to resolve the varied molecular groupings as discrete stained bands. The electron microscope has the ability to reveal whether or not the higher oligomers contain compact groups or extended chains of molecules.</p></div>","PeriodicalId":100924,"journal":{"name":"Micron (1969)","volume":"13 2","pages":"Pages 169-184"},"PeriodicalIF":0.0,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-7206(82)90082-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53858316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Micron (1969)Pub Date : 1982-01-01DOI: 10.1016/0047-7206(82)90084-X
A. Henry Sathananthan, Carl Wood, John F. Leeton
{"title":"Ultrastructural evaluation of 8–16 cell human embryos cultured in vitro","authors":"A. Henry Sathananthan, Carl Wood, John F. Leeton","doi":"10.1016/0047-7206(82)90084-X","DOIUrl":"10.1016/0047-7206(82)90084-X","url":null,"abstract":"<div><p>The fine structure of eight human embryos cleaving in culture are described. Preovulatory human oocytes aspirated at diagnostic laparoscopies were fertilized and developed <em>in vitro</em> by methods which produced normal pregnancies. Three 8-cell and five 10–16 cell embryos showing delayed cleavage were fixed, serially sectioned and examined to determine whether the embryos were developing normally or otherwise.</p><p>The organization of two 8-cell embryos was apparently normal while the other embryos showed varying aspects of abnormal development. Most blastomeres contained organelles normally present in human ova and their fine structure closely resembled those of comparable mammalian embryos. Nearly all the cellular components encountered in early mammalian embryos were observed. Certain morphogenetic changes were also noted during early cleavage involving nuclei, smooth endoplasmic reticulum and mitochondria.</p><p>Both normal and abnormal features of the embryos are reported. Multi-nucleated blastomeres and partial fragmentation were commonly seen in abnormal embryos. The importance of ultrastructural evaluation of embryos in an <em>in vitro</em> programme is revealed in this investigation.</p></div>","PeriodicalId":100924,"journal":{"name":"Micron (1969)","volume":"13 2","pages":"Pages 193-203"},"PeriodicalIF":0.0,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-7206(82)90084-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53858497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Micron (1969)Pub Date : 1982-01-01DOI: 10.1016/0047-7206(82)90104-2
Edward J. McGuire , Robert H. Gray , John A. Lucas , Felix A. de la Iglesia
{"title":"Peroxisome population parameters in rats fed a high-fat diet","authors":"Edward J. McGuire , Robert H. Gray , John A. Lucas , Felix A. de la Iglesia","doi":"10.1016/0047-7206(82)90104-2","DOIUrl":"10.1016/0047-7206(82)90104-2","url":null,"abstract":"","PeriodicalId":100924,"journal":{"name":"Micron (1969)","volume":"13 4","pages":"Pages 467-468"},"PeriodicalIF":0.0,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-7206(82)90104-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53859530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Micron (1969)Pub Date : 1982-01-01DOI: 10.1016/0047-7206(82)90148-0
David G. Pechak
{"title":"Stereologic analysis of the ultrastructure of zoospores of chytriomyceshyalinus","authors":"David G. Pechak","doi":"10.1016/0047-7206(82)90148-0","DOIUrl":"10.1016/0047-7206(82)90148-0","url":null,"abstract":"","PeriodicalId":100924,"journal":{"name":"Micron (1969)","volume":"13 1","pages":"Pages 71-72"},"PeriodicalIF":0.0,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-7206(82)90148-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53860214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Micron (1969)Pub Date : 1982-01-01DOI: 10.1016/0047-7206(82)90047-4
M.I. Whitecross, N. Plovanic
{"title":"Structure of the motor region of pulvinules of Desmodium gyrans lealets","authors":"M.I. Whitecross, N. Plovanic","doi":"10.1016/0047-7206(82)90047-4","DOIUrl":"10.1016/0047-7206(82)90047-4","url":null,"abstract":"","PeriodicalId":100924,"journal":{"name":"Micron (1969)","volume":"13 3","pages":"Pages 337-338"},"PeriodicalIF":0.0,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-7206(82)90047-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53855031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Micron (1969)Pub Date : 1982-01-01DOI: 10.1016/0047-7206(82)90049-8
A.E. Jaunzems, D.H. Ellis
{"title":"Preparation of cultured fibroblasts for the SEM detection of mycoplasma infection","authors":"A.E. Jaunzems, D.H. Ellis","doi":"10.1016/0047-7206(82)90049-8","DOIUrl":"10.1016/0047-7206(82)90049-8","url":null,"abstract":"","PeriodicalId":100924,"journal":{"name":"Micron (1969)","volume":"13 3","pages":"Pages 341-342"},"PeriodicalIF":0.0,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-7206(82)90049-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53855346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}