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Biomedical subjects

J D Harrison

Publications and source records attributed to J D Harrison.

At least 163 records · Page 9Linked to original sources
PubMed1976

Histological effects of ductal ligation of salivary glands of the cat.

Forty-two submandibular, 32 sublingual and 31 parotid glands have been examined microscopically after ductal ligation avoiding the nerves for periods from 1 day to 1 yr. After an initial increase in size, there was over-all atrophy in all three glands. In the parotid gland the response was uniform and there was progressive atrophy until most of the acini were extremely atrophic. However, in the submandibular and sublingual glands the response was very variable, and although in some glands most of the acini were extremely atrophic, in other glands there was far less atrophy and most of the remaining acini appeared more or less similar to normal despite prolonged ligation. These results contrast with those of earlier experimental studies on ductal ligation, but have similarities with observations on the behaviour of human salivary glands.

Animals↗
PubMed1976

Inflammatory cells in duct-ligated salivary glands of the cat: a histochemical study.

Inflammatory cells were studied in submandibular, sublingual and parotid glands of cat following ductal ligation. Macrophages were seen within the parenchyma and associated with extravasated mucin, and were possibly of importance in removing secretory material. Neutrophils were seen interstitially and within the parenchyma. Eosinophils were involved in an initial inflammatory response in interstitial tissue. Fibrous connective tissue was more apparent.

Animals↗
PubMed1976

The effects of ductal ligation on the parenchyma of salivary glands of cat studied by enzyme histochemical methods.

Submandibular, sublingual and parotid glands of cat have been studied following periods of ductal ligation ranging from 1 day to 1 year. An increased prominence of granules of acid phosphatase, beta-glucuronidase and E600-resistant esterase reaction products was sometimes seen in acinar cells and atropic striated ductal cells, and probably represents increased lysosomal enzymic activity, which may be of importance in the adapation of the parenchyma to the altered environment. Other reaction products often appeared to be at normal levels in parenchymal structures that were not very atrophic, and at reduced levels in those that were very atrophic, suggesting a reduction of functional activity in these structures.

Acid Phosphatase↗
PubMed1976

Articulators in dental education and practice.

This study showed that only a small percentage of students continued to use or prescribe articulators after beginning their practices. Yet many restorative teaching programs have utilized semiadjustable articulators with the intent to stimulate a continued use of the instrument in practice. Perhaps the emphasis of instruction should not be placed upon a certain type of articulator for all restorative dentistry but instead upon the selection of an articulator dependent upon the degree of difficulty encountered with each patient. For example, a simple articulator may be used for simple treatment such as a single full gold crown in an otherwise healthy mouth with physiologic occlusion. This does not obviate the need for properly related master and opposing full-arch casts of high quality. Also, instruction is required which will assure that the new crown does not introduce occlusal interferences in centric relation, the intercuspal position, or laterotrusive and mediotrusive excursions. Emphasis should be taken away from teaching use of only one instrument. It should instead be directed toward an understanding of the basic principles of occlusion, cultivating an ability to differentiate the complexity of treatment, and then selecting an instrument which will provide the most practical and suitable result. An effort should be made to compensate for the instrument's limitations by careful clinical examination and correction.

Dental Equipment↗
PubMed1975

Salivary mucoceles.

A survey of natural mucoceles revealed that there were two types, namely, extravasation and retention, and that extravasation mucocceles occurred most often in younger patients and in the lower lip, whereas retention mucoceles occurred most often in older patients and elsewhere in the mouth.

Acid Phosphatase↗
PubMed1975

Experimental salivary mucoceles in cat. A histochemical study.

Ductal ligation of the sublingual gland induced mucocele formation in a high percentage of cats. Extravasated mucus was associated with all sublingual glands up to 20 days after ligation, and extravasation mucoceles were associated with 12 out of 27 sublingual glands between 7 and 365 days after ligation. Enzyme-histochemic examination revealed that the extravasated mucus induced a migration of macrophages and a fibroblastic reaction. It is thought that if these reactions are sufficiently intense in the early days after ligation, then continued spread of extravasated mucus and mucocele formation does not occur; however, if the extravasation is too great to be contained, a mucocele forms in which a balance develops between extravasation of mucus and its removal. Possibly the numerous macrophages in the mucoceles are involved in degrading mucus and facilitating its removal.

Acid Phosphatase↗
PubMed1973

Odontogenic myxoma: ultrastructural and histochemical studies.

An odontogenic myxoma of a maxilla has been examined. Histochemistry of the mucosubstance indicated that hyaluronic acid and chondroitin sulphate were present. On ultrastructural examination many of the cells in the myxomatous tissue were seen with prominent rough endoplasmic reticulum, suggesting a secretory function, and possibly the myxomatous ground substance was produced by these cells. Cells containing collagen fibrils were found. Epithelial islands with intercellular spaces producing an arrangement similar to the stellate reticulum of the enamel organ were found, and possibly had developed from odontogenic epithelial rests. These islands were surrounded by a clear zone, outside which were cells with an increased prominence of adenosine-triphosphatase, nucleoside-diphosphatase, thiamine-pyrophosphatase, and often arylamidase reaction products. This probably represents a reaction of the mesodermal tissue to the epithelial islands. Possibly the epithelium exerts an inductive effect on the mesodermal tissue, and the myxomatous appearance may be the result of an aberrant development of mesodermal cells into ;myxoblasts' which secrete the myxomatous ground substance.

Adenosine Triphosphatases↗