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Biomedical subjects

A M Carpenter

Publications and source records attributed to A M Carpenter.

At least 37 records · Page 2Linked to original sources
PubMed1980

Oval and round window changes in otitis media. Potential pathways between middle and inner ear.

A longitudinal sequential study of oval and round window changes in otitis media in an experimental animal (cat) using Eustachian tube obstruction was done. Thirty-two animals were used. In this first sequential study of the oval and round windows in otitis media, the continuum of round window membrane changes from 1 day to 6 months after obstruction revealed changes to be gradual and similar to those of the mucoperiostium. These changes are suitable for changes in permeability and suggest that this membrane is a very likely pathway from the middle to the inner ear. Bony fistulas were not observed and the oval window remained essentially unchanged in time, thus they were not considered routes into the inner ear. Other possible routes are discussed.

Animals↗
PubMed1979

Infiltration of the tensor tympani and stapedius muscles in otitis media. An experimental study in the cat.

A longitudinal sequential study of otitis media was done in an experimental animal (cat) using eustachian tube obstruction. Fifty animals were used. Cellular infiltration of the tensor tympani and stapedius muscles was studied in a continuum from day 1 to 6 months after inducing otitis media. We observed that there is infiltration of the connective tissue of both muscles in otitis media, and that the cellular changes follow the same pattern as that seen in the mucoperiostium and the round window of the middle ear, although to a lesser degree. In this first report of sequential changes in middle ear muscles in otitis media, clinical implications of these findings are discussed.

Animals↗
PubMed1979

A quantitative histologic study of tissue responses to ramal sagittal splitting procedures.

The viability of bone after sagittal splitting of the mandibular ramus by two techniques was studied. Decalcified sections of bone were studied with light microscopy; ground sections of bone labeled with tetracycline were studied with ultraviolet microscopy. The data indicate that avascular necrosis of the proximal fragment occurs after conventional Obwegeser-Dal Pont sagittal split osteotomy. Viability of the fragment was maintained by using a musculoperiosteal pedicle on the proximal fragment.

Animals↗
PubMed1978

Heterogeneity of the MtTW15 mammosomatotropic tumor. I. Light microscopic evaluation of cell types by means of immunocytochemistry, morphometric quantitation, fluorescence cytophotometry and radioimmunoassay.

Large MtTW15 pituitary tumors produced 200- to 800-fold elevations in serum growth hormone (GH) and prolactin (PRL) levels. Female tumor hosts showed doubling in body weight, milk secretion, and a 2-fold hepatosplenomegaly. Pituitaries of host animals were reduced by about 50% in both weight and concentrations of GH and PRL. Large tumors were well-encapsulated, multinodular and showed variable amounts of necrosis and hemorrhage. Cytofluorometric analysis revealed a range of 100-fold in nuclear DNA content of tumor parenchymal cells which were chromophobic, pleomorphic and frequently mitotic. Concentrations of hormones in tumors were less than in normal pituitaries and highly variable with the ratio of GH/PRL ranging up to 30-fold within the same tumor. Immunostaining and linear scanning quantitation showed that about 50% of the tumor cells contained immunodetectable hormones. Comparison of immunostained adjacent sections showed that hormone-containing tumor cells were pleomorphic, unequally distributed within nodules, lacking in distinctive identifying morphological characteristics and that they contained GH or PRL but not both hormones simultaneously. Collectively our results show that large MtTW15 tumors are comprised of a markedly heterogeneous population of tumor cells and they suggest that the hormone-containing cells are monohormonal secreting tumor cells which can produce GH or PRL but not both hormones.

Animals↗
PubMed1977

Studies of the mechanism of the periodic acid-Schiff histochemical reaction for glycogen using infrared spectroscopy and model chemical compounds.

It has been proposed in the literature that Schiffs reagent reacts with aldehydes to form one of the following types of compounds: alkylsulfonic acids, N-sulfinic acid derivatives, or Schiff bases. Model compounds whose structures are consistent with those proposed in the literature have been synthesized and subjected to infrared analysis. Also, actual products of Schiff reagent reactions with various aldehydes have been isolated and examined using infrared spectroscopy. Comparison of the spectra of the model compounds with those of Schiff-aldehyde reaction products yielded the following conclusions: 1. The reaction of simple organic aldehydes with Schiff's reagent produces an alkylsulfonate-type reaction product. 2. The reaction of periodate-oxidized glycogen with Schiff's reagent probably involves the formation of an alklsulfonate-type compound. 3. The product of the Schiff-aldehyde reaction exists as neither an N-sulfinic acid nor a Schiff base derivative of the fuchsin molecule.

Aldehydes↗