Biomedical subjects
Publications and source records attributed to R W Gaugler.
Standard wounds of simple incision and trauma were made in the gingivae of monkeys. The healing from the 1st to the 21st day was described clinically, histologically, physically and biochemically. There were no major clinical differences, but both atraumatic and traumatic wounds have reactions in the periodontium to be considered in postoperative care.
An endo-1, 3-alpha-D-glucanase (EC 3.2.1.59) was purified from cell-free culture supernatants of Pseudomonas NRRL-B-12324. The enzyme was purified 8.7-fold to a specific activity of 78.1 U/mg of protein. The enzyme was inducible and had an isoelectric point of 4.6 and a Km of 80.0 mM in terms of anhydroglucose units. Two distinct peaks of activity were resolved by gel filtration with two different supporting media, whereas only one peak of activity was resolved by isoelectricfocusing. The two peaks were assigned molecular weight values of 67,400 and 279,000. The pH optimum was near 5.0 and the temperature optimum was near 56 degrees C. Additional gel filtration data indicated that the enzyme functions as an endohydrolase.
Plaque samples were evaluated for fluoride concentration, the degree of the fluoride binding and uptake of fluoride from 1 and 225 parts/10(6) F solutions. The plaque of the caries-free individuals contained significantly higher fluoride concentrations, but no difference was found in binding strength between the caries-free and caries-active groups. Uptake of fluoride from a 1 part/10(6) solution was slightly less for plaque of caries-free recruits, but there was no difference between the groups in uptake from the more concentrated solution.
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Ten laboratory strains of oral microorganisms and 17 recent clinical isolates were examined for their ability to concentrate fluoride from a 1 ppm (0.05 mM NaF( fluoride solution. The laboratory strains concentrated the ion from two- to six-fold over the surrounding media. Clinical isolates of Actinomyces concentrated the ion to similar levels to the laboratory strains of this organism; however, clinical isolates of Streptococcus mutans and S. sanguis concentrated the fluoride significantly less than any of the laboratory strains examined.
The healing of a new attachment procedure was evaluated in monkeys. Standard pedicle wounds similar to reverse bevel flaps were made in previously created periodontal pockets. The diseased root surfaces were treated with sodium deoxycholate (2%) and human plasma fraction Cohn IV (5%), applied to experimental sites for 1 minute each. Control surfaces were similarly treated with phosphate buffered physiological saline. The healing from the first to the 21st day was described (1) clinically, (2) histologically, (3) by rupture strength, and (4) by collagen production assays. All control sites healed with a dentogingival junction comprised only of junctional epithelium. Most experimental sites healed by means of junctional epithelium and some connective tissue new attachment at the apical extent of the wounds.
All the vented samples with sprue widths of 2 mm or more were defect free, whereas the corresponding unvented samples had extensive voids and porosity in all but one casting. All castings with a sprue width of 1 mm were defective regardless of whether or not vents were used. The thickness of the investment above the pattern had no effect on casting results.
Standard wounds of simple incision and partial excision of the dentogingival junction were made in miniature swine. The healing from the 1st to the 14th day were described clinically and histologically, and the standardization of the wounds permitted quantitative and statistical analysis. In wounds that are closely adapted to the tooth, the epithelium of the new dentogingival junction contributes primarily to early wound strength recovery. This functional achievement probably would not occur with thick clots or hematomas, or with any displacement of the gingiva away from the tooth.
Air sampling for beryllium concentrations produced during finishing procedures for a beryllium-containing alloy was conducted in two rooms with capacities of 700 and 10,000 cubic feet. The clearance rate of beryllium in the air and the effect of ventilation and room size on these concentrations were investigated. With local lathe ventilation, no beryllium was found. Without local lathe ventilation, mean 10 minutes concentrations of about 23 mug per cubic meter were found at the breathing zone of the lathe operator in both rooms. At 4 and 8 feet from the breathing zone, sizable concentrations of beryllium above the maximum acceptable standard were found only in the small room. These levels decreased to zero 10 minutes after completion of the finishing and polishing procedure. It was concluded that there was little hazard to dental personnel when local lathe ventilation was used; however, our finding of high concentrations of beryllium in the air when lathe ventilation was not used indicates that continued vigilance must be maintained.
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The isolated cells of the host-dependent meningopneumonitis agent, Chlamydia psittaci, were shown to incorporate radioactive carbon from aspartate, isoleucine, and glucose-6-phosphate into cell lipids. The nature of this incorporation was investigated. Radioactivity was found only in the fatty acids and primarily in the phosphatidyl ethanolamine, and, to a lesser extent, in the phosphatidyl choline fractions. Branched-chain fatty acids, not found in host lipid, were shown to constitute a large proportion of the fatty acid content of phosphatidyl ethanolamine. The reasons why only fatty acid synthesis took place under the conditions of our experiments with isolated meningopneumonitis agent cells remain obscure.
We investigated the effect of the gas environment on the enzymatic reactions of intact isolated cells of the agents of trachoma and of meningopneumonitis of the host-dependent genus Chlamydia. In comparison with the reactions taking place in a gas phase of air, O(2) depressed CO(2) production from pyruvate and glutamate by trachoma and from glutamate by meningopneumonitis. O(2) enhanced the degradation of pyruvate by meningopneumonitis, but this effect was due to increased H(2)O(2), and was reversed by added catalase. Both dehydrogenation of alpha-ketoglutarate and was reversed by added catalase. Dehydrogenation of alpha-ketoglutarate by both agents and production of CO(2) from C(1) of glucose-6-phosphate were stimulated by O(2) and depressed in N(2). The latter activity was stimulated in air, O(2), and N(2) by nicotinamide adenine dinucleotide phosphate (NADP) in relation to the amount added, and also in air or O(2), but not in N(2), by moderate amounts of NADP and an excess of oxidized glutathione with concomitant formation of H(2)O(2). A small but significant amount of O(2) was consumed during the course of these reactions. It is suggested that glutathione reductase activity can occur only when accompanied by an oxidative reaction, and that this close link between the two reactions represents a mechanism of electron transport which transfers hydrogen to molecular O(2).