Speculations based on the morphology of the Golgi systems in several types of proteinsecreting cells

Electron microscopical observations on the relationship of the Golgi region to other intracellular organelles in certain protein-secreting cells have substantiated and extended existing hypotheses. In micrographs of several cell types, the juxtanuclear Golgi regions were observed to be closely associated with nuclear "pores." The "transition elements" of the ergastoplasmic membranes possess "blebs" which may represent a transport process facilitating the movement of intracisternal contents into the Golgi zone. A "blebbing" process of this nature may be one source of the small variety of Golgi vesicles. Zymogen granules of different densities were observed and their significance was postulated. Light Golgi vacuoles were observed. It is suggested that these vacuoles represent accumulations of relatively fluid material segregated from the secretory product in these cell types. These hypotheses from inferential evidence are discussed and extended.

OESTRADIOL METABOLISM IN THE PREVIABLE HUMAN FOETUS AND IN THE FOETO-PLACENTAL UNIT

Five normal previable foetuses were perfused with tracer amounts of oestradiol-4-14C and the metabolism of the compound was investigated. This study was completed by 3 experiments in which the oestradiol-4-14C was introduced in situ into the intact foeto-placental unit via the umbilical circulation.

More than 80 per cent of the radioactive material present in the various foetal organs in both types of experiments was in a conjugated form. In contrast, in the placentas, less than 10 per cent of the total radioactivity present was in a conjugated form.

The bulk of the radioactive material present in the foetal tissues was identified as oestradiol 3-sulphate and oestrone sulphate. In addition, two minor fractions were detected in the perfused foetuses, one of which behaved in countercurrent distribution studies as »glucosiduronates«; the other resembled »sulphates«. The oestrogen moiety of these two fractions was neither oestradiol nor oestrone, but it appeared to be a complex mixture. Although some radioactive material was found which closely resembled oestriol, it was not possible to detect oestriol with certainty.

No glucosiduronate-like material was found in the foetal tissues following the injection of oestradiol-4-14C into the intact foeto-placental unit. Also the quantity of the »sulphate-like« material different from oestradioland oestrone sulphates was greatly reduced:

A number of unconjugated metabolites were also detected, among which oestrone was identified.

A perfusion experiment with an anencephalic foetus indicated that this foetus was capable of forming conjugated metabolites from oestradiol-4-14C.

The results obtained do not favour the view that oestriol is a major and instantaneously formed foetal metabolite of oestradiol. On the other hand, they lend additional support to the concept that oestrogens reaching the foetus are extensively sulphurylated by the foetus and that these oestrogen sulphates are hydrolysed by the placenta before transfer of the oestrogen moiety to the maternal circulation.

IMMUNOFLUORESCENT STUDIES OF THE HISTOPATHOGENESIS OF LYMPHOCYTIC CHORIOMENINGITIS VIRUS INFECTION

LCM virus antigen was visualized in infected tissue cultures and mouse tissues by the direct immunofluorescent procedure. In all instances, antigen was localized to the cytoplasm. In intracerebrally infected mice, antigen was almost completely restricted to meninges, choroid plexus, and ependyma; at no time were neurons involved. Mice infected by intraperitoneal inoculation of a viscerotropic strain demonstrated antigen chiefly in liver parenchyma, splenic reticulum, bronchi, and alveolar cells. Congenitally infected mice showed antigen in almost all cell types observed, but generally in only a minority of cells; infection was often focal in distribution. Liver, kidney, pregnant uterus, and trophoblast were most extensively involved. No antigen was observable in ova of a pregnant mouse.