Survey for aflatoxins and zearalenone in 1973 crop corn stored on farms and in country elevators

A total of 315 marketable and 57 obviously damaged corn samples were collected at 116 different farms and country elevators located in the United States in countries selected from among those producing more than 1 million bushels of corn in 1972. The samples were analyzed for aflatoxins and zearalenone. The most striking correlations observed were between geographical area and mycotoxin contamination. Aflatoxin contamination was most frequently encountered in the Southeast-Appalachia areas with a 44% incidence of marketable corn with detectable aflatoxins. Zearalenone was most frequently encountered in the Corn Belt with 10% incidence in marketable corn from that region. When mycotoxin contamination was found in an establishment, most of the samples from that establishment were contaminated. There was no correlation between mycotoxin contamination and storage practices nor could the observed contamination of marketable corn be related to the contamination of the obviously damaged grain. These observations plus correlations with the geographic incidence and aflatoxin level distribution of published field contamination data suggest the possibility of a common contamination mode.

Autoradiographic studies of cytogenetic effects induced by UV-inactivated measles virus (fusion factor) in human cells

Two types of extensive chromosome changes (pulverization and uncoiling) as well as a combination of these phenomena in the same cell were induced by exposure to UV-inactivated measles virus (FF). The DNA-labeling patterns of these nuclear events were investigated. These types of extensive changes not only appeared to be morphologically distinguishable but also to be induced at different stages of the cell cycle. Pulverization occurred in very actively DNA-synthesizing cells. In contrast, G₁, G₂, or M cells were sensitive to uncoiling changes.

Cytogenetic effects of measles virus fusion factor (FF) on human leukocytes

In human leukocyte cultures, <i>extensive chromosome changes </i>(pulverization, uncoiling, or a combination of these) induced by UV-inactivated measles virus (fusion factor or FF) (1) were virus specific, (2) showed a quantitative relationship to virus dose, and (3) were dependent upon length of virus treatment. In contrast to the above-defined extensive chromosome changes, <i>simple chromosomal breaks </i>showed none of these properties and could be induced by cell debris alone at rates comparable to infectious virus or FF. These observations indicate that extensive and simple chromosomal changes are morphologically distinct and sequentially unrelated, constituting two different populations of aberrations. Analysis of extensive chromosome changes after different virus exposures suggested that uncoiling is not an early and less severe form of pulverization. Localization of chromosome breakage induced by both infectious virus and FF as well as cell debris and control (medium) treated cultures was nonrandom and statistically indistinguishable.