John G. Swift

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Freeze-fracture techniques have been used to study tight junctions on the lateral plasma membrane of cells of the luminal epithelium of the rat uterus under various hormonal regimes. Tight junctions from ovariectomized control rats extended some 0.5 μm down the lateral membrane and the junctional strands often formed a network of closely packed, circular(More)
Small bundles of frog skeletal muscle fibers were loaded with 305 mM K+ and 120 mM Cl-, and 42K+ tracer efflux and influx were measured as a function of external K+ concentration ([K+]o) at a resting potential of -2 mV. As [K+]o was lowered from 305 mM, efflux decreased along a markedly sigmoidal curve, reaching a constant nonzero value at low [K+]o. Influx(More)
The effect of global system for mobile communication (GSM) radiofrequency fields on vascular permeability in the brain was studied using a purpose-designed exposure system at 898.4 MHz. Mice (n= 30) were given a single far field, whole body exposure for 60 minutes at a specific absorption rate of 4 W/kg. Control mice were also sham-exposed (n = 10) or(More)
The structural relationships between intramembranous particles (IMPs) and surface carbohydrates have been studied in cells of a compact tissue--uterine epithelial cells--using an in vivo technique. This involves introducing small amounts of glycerol into the uterine lumen of anaesthetized rats. The treatment results in extensive aggregation of IMPs in the(More)
The freeze-fracture technique has been used to study the organization of intercellular junctions in two cases of hepatocellular carcinoma. A tumor free cirrhotic liver has been included for comparison. Tight junctions were disorganized in the tumor cells of hepatocellular carcinoma. The tight junction networks often were not orientated parallel to the(More)
The ultrastructure of tight junctions between uterine luminal epithelial cells of the pregnant rat was studied by the freeze-fracture technique. On day 5 of pregnancy, the day of implantation, the region of tight junctions extended three times as far down the lateral cell membrane as on day 1 of pregnancy, and the strands of the complex interlinked more(More)
In previous work we have shown that ovarian hormones, when injected into ovariectomized rats, alter the fine structure of the plasma membrane of endometrial epithelial cells. In this paper freeze-fractures have been used to study the apical plasma membrane of endometrial epithelial cells of rats during the period of blastocyst implantation of normal(More)