In this report over 400 subgingival plaque samples taken from over 110 patients were examined microscopically and culturally for 30 bacterial parameters. The patients could be placed into six disease categories based upon clinical criteria. The bacterial profile of each clinical category was generally distinctive of that category. Periodontal patients who had been successfully treated and maintained had plaques that were populated by significantly higher proportions of Streptococcus sanguis, Actinomyces viscosus, A. odontolyticus and S. mutans and significantly lower proportions of B. gingivalis and spirochetes compared to the five untreated disease categories. The spirochetes were the overwhelming microbial type in the plaques of adult periodontitis (AP) patients, averaging about 45% of the microscopic count. The bacteriological results could not distinguish between ADA Type III and IV periodontitis, suggesting that the same type of infection was occurring in an active site in any AP patient. The patients designated as early onset periodontitis (EOP) differed from the other patients by their relative youth and by their significantly higher proportions of Bacteroides gingivalis and/or B. intermedius. Two types of EOP were recognized in which the most diseased variant was characterized by having an average of 49% spirochetes in the plaque. Four localized juvenile periodontitis (LJP) patients were notable in not having detectable A. actinomycetemcomitans. The data indicate that the various types of periodontitis, with the possible exception of LJP are specific anaerobic infections involving spirochetes and to a lesser extent B. gingivalis and B. intermedius.

TX. bial agents.10,11 Shinn reported in 1962 that systemic metronidazole quickly and dramatically improved the oral condition known as acute necrotizing ulcerative gingivitis (ANUG) or trench mouth.12 As ANUG had been considered to be an anaerobic fuso-spirochetal infection,13 Shinn's results lead to the demonstration that metronidazole is a specific inhibitor of anaerobic bacteria.14"15 Subsequently, it was shown that the efficacy of metronidazole in ANUG could be associated with a significant reduction in spirochetes and in Prevotella intermedia,16 one of several blackpigmented anaerobic (Bacteroides) species found in periodontal plaques.The similarity of the anaerobic flora found in ANUG to the anaerobic flora found in adult Periodontitis (AP)1,4 suggested that metronidazole could be effective in the treatment of AP. Two double-blind studies, each using different protocols and dosages, showed that metronidazole was effective in reducing probing (pocket) depths and in increasing apparent attachment level about the most severely involved teeth.10,17 A third study showed that metronidazole plus de-248 EFFECTS OF METRONIDAZOLE ON PERIODONTAL TREATMENT NEEDS J Periodontol

Digital subtraction radiography requires close matching of the contrast in the films to be subtracted. A digital method is presented permitting the retrospective correction of film contrast differences. The method is nonparametric and derives the required gray level transformation directly from the histograms associated with the radiographs. This transform is shown to be unique and monotonic. It is based on fewer theoretical assumptions than a previously described parametric correction method, and it performs significantly better in reducing the contrast mismatch measured by the standard deviation of the gray levels in the subtraction image.

No abstract

Recent studies have shown that the extent of hydrolysis by plaque of the trypsin substrate, N-benzoyl-DL-arginine-2-naphthylamide (BANA), correlates with the numbers and proportions of spirochetes in subgingival plaque samples, and appears to be an indicator of clinical disease. In this study, BANA hydrolysis by subgingival plaque was evaluated in a blind manner for its ability to reflect both clinical parameters and subgingival levels of bacteria and spirochetes. Subgingival plaque samples were collected from periodontally healthy and diseased sites in 23 untreated periodontal patients and in 13 treated and maintained periodontal patients. In untreated patients, BANA hydrolysis was statistically associated with the total number of spirochetes and bacteria in the plaque sample, but in the treated patients BANA hydrolysis was statistically associated only with the spirochetes. Most BANA-positive reactions in both patient groups were from the sites which were clinically diseased and high in spirochetes. The majority of the negative reactions for BANA hydrolysis in both patient groups was among the sites which were periodontally healthy and low in spirochetes. Specificity and sensitivity of the test were above 80% for disease status in untreated patients. The predictive value of a positive and negative test was above 83%. Slightly lower sensitivity, specificity, and predictive values were found in the treated group. The BANA reaction appears to be an accurate and simple indicator of both clinical disease status and plaque levels of spirochetes in individual tooth sites in untreated and treated periodontal patients.

Changes in the periodontal alveolar bone are often evaluated by comparing a series of radiographs taken over time. This investigation used a technique that allowed the image registration to be geometrically standardized each time a radiograph was taken. Radiographs of 24 patients from an ongoing double-blind, clinical study using metronidazole were obtained: (1) before any treatment, (2) at the completion of scaling and root planing and surgery (when performed) and (3) during the maintenance phase. One hundred six (106) paired comparisons were analyzed by subtraction radiography using a computerized system. Of these, 95 (89%) exhibited a minimal degree of geometric distortion and could be successfully substracted. Most areas (67%) showed no change in bone structure following periodontal treatment. Bone gain was noted in 12% of the sites examined, while bone loss was seen in 21% of the sites. This bone loss was statistically associated with sites that had received some form of surgical treatment.

DC vaccines/dendritic cell development/fetal calf serum-free culture conditions for DC/in vivo therapeutic DC approaches.

We studied in vivo responsiveness of venous alpha 1- and alpha 2-adrenoceptors, measuring the diameter changes in superficial veins in response to alpha-adrenergic agonists and antagonists in healthy human volunteers. The dorsal hand vein technique was used because it permits complete dose-response studies of venous constriction without confounding reflex alterations. Local infusions of all agonists studied induced dose-dependent contraction of the hand vein; the maximal effects (Emax) were: norepinephrine (88% +/- 10%), methoxamine (97% +/- 5%), phenylephrine (95% +/- 6%), clonidine 54% +/- 12%), and azepexole (68% +/- 26%). Clonidine reduced the norepinephrine-induced venoconstriction by 11% +/- 10%. Oral doses of 1 mg prazosin antagonized the venoconstriction induced by norepinephrine, methoxamine, and clonidine, but not by azepexole. Yohimbine-antagonism was observed against all agonists studied. Inhibition by yohimbine of clonidine-induced venoconstriction was irreversible over 60-180 min. Results show that the in vivo effects on veins of alpha-adrenergic agonists are in good agreement with results from in vitro experiments. Agonists with alpha 1- and alpha 2-adrenoceptor subtype selectivity cause venoconstriction in vivo, but alpha 2-receptor mediated constriction is intrinsically weaker. Clonidine acts as a partial antagonist against norepinephrine, presumably on postsynaptic alpha 2-receptors. At high doses, alpha 2-adrenoceptor subtype selectivity of clonidine and yohimbine appear to be partially lost in vivo.