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Localization of carboxyl groups in gastric mucosa as possible sites of gastrin (1969)

Coalson, Robert E.

Springer

Cell & tissue research 101 (1969), S. 241-253

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ISSN: 1432-0878

Keywords: Cytology ; Gastric mucosa ; Histocytochemistry ; Gastrin ; Zollinger-Ellison syndrome

Source: Springer Online Journal Archives 1860-2000

Topics: Biology , Medicine

Notes: Summary Human and pig gastrins contain a sequence of five consecutive glutamic acid residues. An attempt was made to localize gastrin using methods known or assumed to operate on a carboxyl mechanism. General methods for acidic groups were combined with selective blocking (methylation) and unblocking (saponification) methods to increase COOH specificity. Epithelial cells with weakly metachromatic granules could be identified in untreated sections stained with toluidine blue (pH 5). After prolonged methylation and saponification, the same and previously obscured cells were moderately to intensely metachromatic, this residual basophilia attributable to weak COOH groups. Specifically marked metachromatic cells were iron-positive after colloidal iron staining, but were delineated easily only after methylation-saponification. Metachromatic cells were also clearly demonstrated by the carboxyl method of Barrnett and Seligman and by silver impregnation (pH 5). The granular metachromatic cell demonstrated by these methods contains significant amounts of a weakly acidic component which the Barrnett-Seligman reaction indicates to be glutamic acid. Comparable staining results were obtained with gastrin producing Zollinger-Ellison islet cell adenomas. It is postulated that the COOH-rich substance is gastrin or gastrin precursor and that the metachromatic cell is responsible for its production.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00335731

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Initial events in interactions of blood with a foreign surface (1969)

Baier, Robert E. ; Dutton, Robert C.

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 3 (1969), S. 191-206

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ISSN: 0021-9304

Keywords: Chemistry ; Polymer and Materials Science

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Medicine , Technology

Notes: The nature of the events occurring immediately after exposing foreign surfaces to fresh flowing blood was assessed using a combination of MAIR infrared spectroscopy, ellipsometry, and contact angle measurements. Within the first 5 sec after contact with blood issuing from the jugular veins of lightly anesthesized dogs, germanium prisms were uniformly coated with strongly adherent proteinaceous filsm having an average optical thickness equivalent to 2 layers of stearic acid (approx. 50 Å) and having critical surface tensions of about 36 dyne/cm. A contact time of 60 sec led to a less uniform coating of average optical thickness equivalent to 5 layers of stearic acid (approx. 125 A), but with similar MAIR spectrum and wettability. The internal refelection spectra were consistent with the presence of either alpha-helical or random-chain configurations, but not with the extended chain beta-structure for proteins. Films cast from purified fibrinogen on platinum foils gave similar spectra and exhibited similar wetting properties; these observations are consistent with the hypotehsis that initial adsorptive events are dominated by fibrinogen deposition. The involvement of small amounts of lipid or other protein remains a distinct possibility, however.

Additional Material: 6 Ill.