A New Freezing-Ultramicrotome

Moor, H.; Mühlethaler, K.; Waldner, Hanspeter; Frey‐Wyssling, A.

doi:10.1083/jcb.10.1.1

Cited by 378 publications

(73 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Samples were freeze-etched in a Balzers 360M freeze-etching plant (Balzers A. G., Lichtenstein) by the method of Moor et al (1961). The table temperature was -100°C and the knife temperature -150°C.…”

Section: Electron Microscopymentioning

confidence: 99%

An Electron-Microscope Study of Naturally Occurring and Cultured Cells of Neisseria Gonorrhoeae

Novotny

Short

Walker

1975

Journal of Medical Microbiology

View full text Add to dashboard Cite

FOR the development of an effective gonococcal vaccine it is likely that knowledge of virulence factors is required so that antigens of possible protective value can be defined. It is then necessary to determine whether such protective antigens are produced by gonococci cultured in vitro.Much of the work being carried out at the present time on gonococci was stimulated by the discovery by Kellogg et al. (1963) of four different colonial types designated Tl-T4. Although all the colony types derived from a single strain were virulent for human volunteers for up to 38 selective passages, only T1 and T2 colonies were able to produce the disease after several hundred passages (Kellogg et al., 1968).Work on the gonococcus has been hampered by the lack of an animal model, since the only susceptible species appear to be man and chimpanzees (Lucas et a!., 1971). Recently, however, there have been reports that claim to measure virulence by simple in-vivo procedures. Ark0 (1972Ark0 ( , 1973 used implanted capsules in laboratory animals to cultivate gonococci in vivo and showed that the avirulent types when injected into these were cleared much faster than virulent types. The model was also useful in the study of active immunisation (Arko, 1974). Buchanan and Gotschlich (1973) demonstrated that T1 and T2 gonococci survived for longer periods than their T3 and T4 counterparts when inoculated on the chorioallantoic membrane of embryonated eggs. Bumgarner and Finkelstein (1 973), although failing to support this finding, showed remarkable differences in virulence between the types on intravenous injection into 1 1-day-old chick embryos. In addition, experiments with human polymorphs have shown that T1 cells are retained to a greater extent and are more resistant to digestion than T4 cells (Thomas, Hill and Tyeryar, 1973) and that virulent cells have greater resistance to phagocytosis (Ofek, Beachey and Bisno, 1974). Human bactericidal serum (Thomas et al., 1973) or rabbit antiserum to T2 gonococci enhanced phagocytosis of virulent but not avirulent cells (Ofek et al., 1974).Although it is possible by laboratory culture to distinguish colonies of Neisseria gonurrhoeae that are believed to be virulent, the factors responsible for virulence are far from clear. Jephcott, Reyn and Birch-Andersen (1971) and independently Swanson, Kraus and Gotschlich (1971) demonstrated that gonococci of colonial types T1 and T2 were piliate whereas those of T3 and T4 were not. As this appeared to be the most significant morphological difference between the virulent and avirulent colony types it was thought that piliation might be the factor that conferred virulence. Although in describing these appendages the term fimbriae has a prior claim over that of pili (Brinton, 1965 ;Duguid, Anderson and Campbell, 1966), the latter is in more general use as applied to gonococci and is used throughout the

show abstract

Section: Electron Microscopymentioning

confidence: 99%

An Electron-Microscope Study of Naturally Occurring and Cultured Cells of Neisseria Gonorrhoeae

Novotny

Short

Walker

1975

Journal of Medical Microbiology

View full text Add to dashboard Cite

show abstract

“…Given the above introduction, it is perhaps fitting and appropriate that the first issue of HCB in 2018 includes a review of the technique of freeze fracture for the ultrastructural analysis of cellular membranes, which was reported about 60 years ago (Steere 1957;Moor et al 1961). In this technique, aldehyde-fixed cells or pieces of tissues are cryoprotected followed by rapid freezing and fracturing by a microtome in a liquid nitrogen cooled apparatus under a high vacuum.…”

Section: Perspectives On Freeze Fracture For Ultrastructural Analysesmentioning

confidence: 99%

In focus in HCB

Taatjes

Roth

2017

Histochem Cell Biol

View full text Add to dashboard Cite

“…The results of this study demonstrated that (1) gap junctions are already present in cultures of near confluent induced pluripotent stem cells derived from human cord blood, and (2) these gap junctions indeed express Cx43. Moreover, and quite fittingly, this study also elegantly demonstrates the modern use of the freeze-fracture technology, first described 55 years ago by Moor et al (1961) combined with immunogold labeling to resolve a contemporary question in cell biology (refer to the cover image of this issue). This should serve as a reminder to us all that techniques from the twentieth century may still be quite relevant in the twenty-first.…”

mentioning

confidence: 96%