Patricia D. Peters

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A common tattoo occurring in the mouth is caused by the insertion of amalgam filling material into the soft tissues. Fifteen amalgam tattoos were examined. Amalgam or its derivatives were found within macrophages, fibroblasts and multinuclear giant cells. Fine particles were found associated with: the basement-membranes of mucosal epithelium, of striped(More)
Sites with high calcium affinity in Paramecium aurelia were identified by high calcium (5 mM) fixation and electron microscope methods. Electron-opaque deposits were observed on the cytoplasmic side of surface membranes, particularly at the basal regions of cilia and trichocyst-pellicle fusion sites. Deposits were also observed on some smooth cytomembranes,(More)
X-ray microanalysis of frozen-hydrated tissue sections permits direct quantitative analysis of diffusible elements in defined cellular compartments. Because the sections are hydrated, elemental concentrations can be defined as wet-weight mass fractions. Use of these techniques should also permit determination of water fraction in cellular compartments.(More)
A number of embedding media were checked for chlorine content by means of X-ray analytical electron microscopy (EMMA-4 electron microscope and KEVEX energy dispersive analyser). It was shown that the technique based on glutaraldehyde—urea polymerisation (Pease and Peterson, 1972) is satisfactory for use in ultrastructural detection of chloride ions by means(More)
The epithelium and the lumen of the Malpighian tubules of the housefly contains mineralized dense bodies called concretions. The morphological characteristics, mode of origin, nature of the sequestered elements and the age-associated changes in the distribution of concretions are reported. There are three types of concretions in the cytoplasm, which have(More)
The Bacillus subtilis gene encoding CheB (cheBB), the chemotactic methylesterase, has been sequenced. The 39-kDa protein which resulted from the expression of cheBB, using a T7 expression system was consistent with the predicted open reading frame. CheBB shares 39.5% identity with Escherichia coli CheBE and can complement a cheBE null mutant. CheBB is(More)
Bacillus subtilis cheRB, which encodes the chemotactic methyltransferase, has been cloned and sequenced. CheRB is a polypeptide of 256 amino acids, with a predicted molecular mass of 28 kDa. A comparison of the predicted amino acid sequence of B. subtilis CheRB with that of Escherichia coli CheRE demonstrates that the two enzymes share 31% amino acid(More)
Giant axons from the squid, Loligo pealei, were fixed in glutaraldehyde and postfixed in osmium tetroxide. Calcium chloride (5 mM/liter) was added to all aqueous solutions used for tissue processing. Electron-opaque deposits were found along the axonal plasma membranes, within mitochondria, and along the basal plasma membranes of Schwann cells. X-ray(More)
The contractile responses to barium and the ultrastructure and ionic composition of mitochondria were studied in vascular smooth muscle. In normal rabbit portal anterior mesenteric vein (PAMV) and main pulmonary artery (MPA) smooth muscle mitochondria were frequently associated with the surface vesicles. The average distance between the outer mitochondrial(More)
Large amounts of calcium and phosphorus have been found by electron-microprobe analysis in the dense bodies of frozen-dried, human platelets. The calcium and phosphorus occurred in a fixed ratio that was similar to that in dicalcium ATP. No other elements were detectable except chlorine. Minute, electron-dense disks were found in the surface membranes of(More)