An electron microscopic study of early developmental stages, myogenesis, oogenesis and cnidogenesis in the anthomedusa,Podocoryne carnea M. Sars

Detection of glycogen and glycogen synthetase activity in the hepatic primordium of chick embryo at early developmental stages Glycogen has been detected cytochemically in the chick hepatic primordium at early developmental stages. The cytochemical methods used are PAS according to Hotchkiss & MacManus after fixation by Gendre's fluid at −20 °C and rapid dehydration at 4 °C and Thiery's technique for polysaccharide detection at the electron microscopic level. Previous authors reported that glycogen appears in the hepatocytes during the sixth or seventh day of incubation in the chick embryo. In fact, the more sensitive methods used here show that this substance is present in the determined presumptive hepatic endoderm as early as the 20-somite stage, some hours before the formation of the primary hepatic bud. Glycogen is present in an approximately constant amount in the differentiating hepatic endoderm as β particles (according to Drochmans' nomenclature) from the 20-somite stage to the sixth day of incubation. Then the hepatocyte glycogen content increases rapidly as had previously been shown by biochemical methods and α rosettes appear in the cell. A glycogen synthetase activity has been detected at the end of the fourth day of incubation (96 h). This activity increases sharply from the sixth day of incubation to reach a maximal value at .12 days and then decreases until hatching. The possible regulatory mechanisms of glycogen synthesis in differentiating liver cells of avian embryos are discussed.

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Electron-microscopic study of developmental stages of Goussia balatonica and G. pannonica (Apicomplexa: Eimeriorina), parasites of white bream Blicca bjoerkna

Diseases of Aquatic Organisms ◽

10.3354/dao013095 ◽

1992 ◽

Vol 13 ◽

pp. 95-101 ◽

Cited By ~ 1

Author(s):

K Molnár ◽

F Baska

Keyword(s):

Microscopic Study ◽

Electron Microscopic Study ◽

Developmental Stages ◽

Electron Microscopic ◽

White Bream

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The Growth of Herpesvirus mulatto in Human Fibroblast

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051232 ◽

1974 ◽

Vol 32 ◽

pp. 244-245

Author(s):

Glennelle Washington ◽

Philip P. McGrath ◽

Peter R. Graze ◽

Ivor Royston

Keyword(s):

Rhesus Monkey ◽

Microscopic Study ◽

Electron Microscopic Study ◽

Peripheral Blood ◽

Human Fibroblast ◽

Rhesus Monkeys ◽

Human Fibroblasts ◽

Electron Microscopic ◽

Specific Antisera ◽

Peripheral Blood Leucocytes

Herpes-like viruses were isolated from rhesus monkey peripheral blood leucocytes when co-cultivated with WI-38 cells. The virus was originally designated rhesus leucocyte-associated herpesvirus (LAHV) and subsequently called Herpesvirus mulatta (HVM). The original isolations were from juvenile rhesus monkeys shown to be free of antibody to rhesus cytomegalic virus. The virus could only be propagated in human or simian fibroblasts. Use of specific antisera developed from HVM showed no relationship between this virus and other herpesviruses. An electron microscopic study was undertaken to determine the morphology of Herpesvirus mulatta (HVM) in infected human fibroblasts.

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Cell Wall Ultrastructure in Three Strains of a Cariogenic Streptococcus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065730 ◽

1971 ◽

Vol 29 ◽

pp. 338-339

Author(s):

M. J. Kramer ◽

Alan L. Coykendall

Keyword(s):

Cell Wall ◽

Dental Caries ◽

Streptococcus Mutans ◽

Microscopic Study ◽

Electron Microscopic Study ◽

Genetic Heterogeneity ◽

Morphological Characteristics ◽

Electron Microscopic ◽

Dna Reassociation ◽

Wall Ultrastructure

During the almost 50 years since Streptococcus mutans was first suggested as a factor in the etiology of dental caries, a multitude of studies have confirmed the cariogenic potential of this organism. Streptococci have been isolated from human and animal caries on numerous occasions and, with few exceptions, they are not typable by the Lancefield technique but are relatively homogeneous in their biochemical reactions. An analysis of the guanine-cytosine (G-C) composition of the DNA from strains K-1-R, NCTC 10449, and FA-1 by one of us (ALC) revealed significant differences and DNA-DNA reassociation experiments indicated that genetic heterogeneity existed among the three strains. The present electron microscopic study had as its objective the elucidation of any distinguishing morphological characteristics which might further characterize the respective strains.

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