Philip Person

Jawbone cavities and trigeminal and atypical facial neuralgias

The possible role of dental and oral disease in the etiology of idiopathic trigeminal and atypical facial neuralgias has been examined. Among thirty-eight patients with idiopathic trigeminal neuralgia and twenty-three patients with atypical facial neuralgia, there was in nearly all instances a close relationship between pain experienced and the existence of cavities in alveolar bone and jawbone of the patients. The cavities were at the sites of previous tooth extractions and, although at times more than 1 cm. in a given diameter, were usually not detectable by x-rays. A new method for their detection and localization was developed empirically, based on the observation that peripheral infiltration of local anesthetic into or very close to the bone cavity rapidly abolished trigger and pain perception by patients during persistence of the anesthetic action. Histopathologic examination of bone removed from cavities by curettage revealed, in both idiopathic trigeminal and atypical facial neuralgias, a similar pattern characterized by a highly vascular abnormal healing response of bone. Some lesions presented a mild chronic inflammatory (lymphocytic) infiltration. Preliminary microbiologic studies of material from the walls of the cavities showed the existence within them of a complex, mixed polymicrobial aerobic and anaerobic flora. Treatment consisted of vigorous curettage of the bone cavities, repeated if necessary, plus administration of antibiotics to induce healing and filling-in of the cavities by new bone. Responses of patients to the above treatment consisted of marked to complete pain remissions, the longest of which has been for 9 years. Complete healing leads to complete and persistent pain remissions. It was concluded that in both idiopathic trigeminal and atypical facial neuralgias, dental and oral pathoses may be major etiologic factors.

AEROBIC OXIDATIVE METABOLISM OF SALIVARY GLANDS

The concept that respiratory processes provide the energy required for salivary gland secretion can be traced back to 1886, when Chauveau and Kaufmann first reported an increased oxygen consumption by the secreting parotid g1and.l Since then, numerous experiments have established the existence of a positive relation between salivary secretion and aerobic oxidation. Earlier experiments performed, for the most part, with glands stimulated to greater secretion indicated that the increase in secretory activity was paralleled by a corresponding increase in oxygen consumption. Such studies showed that chemical or electric stimulation of salivary secretion in vivo by intact submaxillary glands produced a significant increase in glandular oxygen ~ p t a k e . ~ ~ A similar increase in oxygen utilization was shown to occur in vitro when salivary tissue slices were exposed to secretory stimulants, such as acetylcholine, eserine, and pilocarpine, whereas sections incubated anaerobically under identical conditions did not r e s p ~ n d . ~ . ~ More recently, a converse approach, based upon the use of nonsecreting glands, confirmed the previously established relationship between oxygen utilization and salivary secretion. By ligating the submaxillary excretory duct, Junqueira and his co-workersZ7 produced submaxillary glands in a so-called resting condition in which the glands, while not secreting, remained capable of secreting upon adequate stimulation. Such nonsecreting glands had a significantly lower oxygen consumption and a lower high-energy phosphorus content than did the nonligated controls; anaerobic glycolysis again remained unaffected by the secretory state of the gland.7*8 Additional information bearing on the role of oxidative processes in salivary functions comes from recent studies demonstrating that glandular alterations caused by severe X irradiation and acute starvation are accompanied by disturbances in salivary gland aerobic intermediary carbohydrate m e t a b o l i ~ m . ~ J ~ Moreover, iodide concentration and iodotyrosine synthesis by submaxillary homogenates both have been shown to be mediated by aerobic oxidative reactions involving an iodide peroxidase.ll Finally, a current report reveals that salivary glands possess an unusually high monoamine oxidase activity.I2 The present study was prompted by the need for additional relevant data that will lead to an increased understanding of the oxidative processes operating in salivary glands. Our immediate objective was a comparison of the aerobic oxidative capacities of the two main types of epithelial structures comprising the salivary gland parenchyma, that is, acini and ducts.* The two approaches employed were (1) a conventional histochemical technique that permits the visual comparison of oxidase activity in terms of the intensity of the indophenol blue reaction in frozen tissue sections and ( 2 ) an original differential centrifugation procedure that permits the quantitative estimation of cytochrome oxidase activity in isolated acini and in isolated ducts.

MEDIATION OF p-AMINODIPHENYLAMINE OXIDATION VIA CYTOCHROME OXIDASE

Manometric studies have revealed that the oxidation of p-aminodiphenylamine by Keilin and Hartree beef heart muscle particles was several-fold higher in the presence of added cytochrome c than in the absence of the pigment. The oxidation of p-aminodiphenylamine was inhibited 90% by 10–4 M cyanide. Correlated spectrophotometric studies demonstrated that the oxidation of p-aminodiphenylamine by Keilin and Hartree particles and fresh-frozen dehydrated tissue sections produced substances with identical visible and ultraviolet absorption spectra. The above experiments further indicate that the oxidation of p-aminodiphenylamine is mediated via cytochrome oxidase, and that this reagent provides valid histochemical localizations of the respiratory enzyme.

Biochemical and Histochemical Studies of Aerobic Oxidative Metabolism of Oral Tissues. II. Enzymatic Dissection of Gingival and Tongue Epithelia from Connective Tissues

The interpretation of biochemical and metabolic studies of intact tissues, tissue slices, and tissue homogenates may be extremely difficult when different cell types are present, because one cannot ordinarily assess the relative contribution of each cell type to the over-all activity exhibited by the tissue preparation. Histochemical techniques may provide qualitative and, less frequently, semiquantitative or quantitative information concerning relative activities of the different tissue components. Previous studies from this laboratory dealing with aerobic metabolism of gingiva1 and of salivary glands2 have demonstrated an urgent need for separating the epithelial components of oral tissues from their associated connective tissues to permit quantitative biochemical estimations of the metabolic activities of the separated cell types. For salivary glands, this problem was solved in our laboratory by the development of a combined mechanical crushing and differential centrifugation procedure, permitting isolation of relatively pure, separate acinar and duct fractions, whose respective biochemical and metabolic properties could be determined.3 4 The present paper will deal with the problem of the separation of gingival and tongue epithelia from their underlying connective tissues, with retention of the activities of their labile terminal respiratory metabolic systems. A preliminary oral report on aspects of this work was made at the Second International Conference on Oral Biology in Bonn, Germany, July, 1962. At the same time there appeared an abstract by Araya, Imagawa, and Shizuya,5 in which they reported

SOME OBSERVATIONS ON THE EVOLUTION OF ORAL TISSUES

Since we are currently celebrating the centennial of Charles R. Darwin’s The Origin of Species it seems especially appropriate to begin a publication such as this, in which so many disciplines of biology are represented, upon a theme of evolution. Perhaps no vertebrate structures have received more detailed evolutionary study than have teeth and jaws. Even so, few who work with oral tissues are aware of their importance in some of the great problems of biological evolution. Neither is it generally appreciated that there is much in the story of the evolution of oral structures that can improve our understanding of, and approach to, problems of oral tissue metabolism. Some preliminary remarks concerning these matters are therefore in order. Nearly all the great evolutionary advances have involved major changes in food-getting. Edwin H. Colbert has said that in the course of vertebrate evolution the appearance of jaws constituted a major revolution whose importance cannot be overestimated.’ Why this should be so may be easily understood from the following brief passage taken from Homer W. Smith’s From Fish to Philosopher: “Without the predatory power of jaws and teeth and the possibility of swift and accurate pursuit of prey there would have been no evolution of the distance-sense organs of smell, sight and hearing, of elaborate muscular coordination, of prevision of how to get from here to there and the possible consequences of the transit-in short, there would have been no centralization of the nervous system such as ultimately produced the brain, and the earth would never have known the phenomenon of consciousness, at least of an order superior to that of the lobster, scorpion, or butterfly.”* Another reason, readily appreciated, for the very great importance of the teeth and jaws in evolutionary studies is their relative indestructibility. This is especially the case in respect to problems of the origin of man. Quite frequently the remains of man, apes, monkeys, and related mammals consist solely of broken jaws with a few teeth. These structures therefore may constitute the only evidence from which anthropologists and paleontologists must evaluate the hominid character of such remains. For this reason the morphologies of the jaws and teeth have become reference criteria in investigations of the origin of man as well as of other problems of ev0lution.~*4 It is not generally known that another major reason for the critical impor-

The metabolism of oral tissues

Abstract In discussing the metabolism of oral tissues, we have touched on many disciplines of biology. The problem begins in the phylogenetic and evolutionary aspects of the development of oral structures, which are reflections of the metabolism of our ancestors, and continues into the ontogenetic aspects capable of supplying valuable and fundamental information at all stages of the individuals history. The possible levels of metabolic study are from the intact organism to its subcellular and molecular units of life. To reiterate, in the mouth and its associated structures, are found nerve, blood vessel, muscle, gland, connective tissue, epithelium, bone, and also highly specialized tissues not found elsewhere, such as cementum, dentine, and enamel. These tissues obey the same fundamental laws and exhibit the same basic biologic phenomena that are found elsewhere in the body. Many of the oral structures are close to the bodys exterior and are more easily observed and more accessible than any others of comparable metabolic activity. In addition, they usually require less manipulation and are subjected to less trauma in experimental situations. We have stressed the unique possible application of oral tissue metabolism studies in relation to problems of cell respiration. Our purpose has been to stress some of the fascinating problems involved in study of the oral tissues and to point to some of the potentialities of their use for the study of fundamental biologic phenomena.

Development of chick limb bud chondrocytes in cell culture: morphologic and oxidative metabolic observations.

For the purpose of describing early chondrogenic metabolic and structural events, measurements were made of oxidative and other enzymatic activities at various stages in the morphologic development of chondrocytes over a period of 18 to 20 days in continuous cell culture. Comparisons were also made between cells grown in 20% O2 and in 35% O2. These cultures exhibited rapid confluence (within 24 hours), early development of cartilaginous nodules by Day 2 to 3 and metachromatic staining of the chondrocyte matrix by Day 3 to 4. Under 35% O2, cell sheets were thicker and there was increased pleomorphism of chondrocyte and fibroblast cell types, with a relative increase of fibroblast components and reduction in chondroblasts and chondrocyte aggregates. Using the von Kossa staining procedure, calcium salt deposition was observed by Day 9. There was no apparent difference in mineralization of cultures grown under the low and high O2 tensions. Under normoxic conditions cytochrome oxidase and malate dehydrogenase (MDH) activities increased rapidly for the first three to four days and then remained essentially constant. Lactate dehydrogenase (LDH) activity increased continuously over the life of the culture. Acid phosphatase increased rapidly until about Day 13 after which it remained constant, whereas alkaline phosphatase showed a bimodal activity profile. Under hyperoxic conditions, cytochrome oxidase, MDH and alkaline phosphatase activity were significantly inhibited. LDH and acid phosphatase activities were markedly inhibited initially but with time showed a degree of recovery.

THE FATE OF WURSTER'S RED FREE RADICAL IN TISSUES WITH HIGH AND LOW OXYGEN UTILIZATIONS (HEART MUSCLE AND GINGIVA)

When N,N-dimethyl p-phenylenediamine is incubated with fresh frozen sections of rat heart muscle, there is a rapid, enzymatic, single electron oxidation of the diamine to form the pink Wursters free radical with absorption maxima at 550 and 510 nm. This is followed by radical dimerization and other interactions to form a purple color accompanied by a new peak at 660-670 nm and finally a substantive blue dye. In contrast, with frozen sections of gingiva, instead of the pink color of the Wursters free radical, one first sees a green color which slowly changes to blue. If heart muscle is kept at room temperature for 30-60 min or in a deep freeze for several days prior to use, it also exhibits formation of the green color. Spectrophotometric studies of the above tissue systems reveal that the new green color does not represent formation of a new compound with new absorption maxima. The same absorption maxima are present in each of the above systems; however, there are differences among the systems with respect to the rates of formation of the absorption maxima in different regions of the spectrum. The latter phenomena produce the color changes seen by the eye. It is suggested that the kinetics of Wursters Red free radical interactions in tissue may be dependent upon the metabolic (redox) status of the tissue.