Five cases are reported of periodontitis affecting the deciduous teeth in young children. The purpose of the report is to define prepubertal periodontitis as a clinical entity, establish diagnostic criteria, demonstrate clinical, radiographic, and historical features, document progression, and explore methods of treatment. The disease occurs in localized and generalized forms. In the localized form, either few teeth or many may be affected. The onset appears to be around the age of 4 years or before. The gingival tissue manifests only minor inflammation, if any, and microbial plaque is minimal. Alveolar bone destruction proceeds more rapidly than in adults or teenagers with periodontitis, but much slower than in individuals with generalized prepubertal periodontitis. In some cases, otitis media and upper respiratory infections are also present, although these are not life‐threatening. The progress of the disease can be halted, so far as is known, by curettage coupled with antibiotic therapy and improved toothbrushing. The hallmarks of generalized prepubertal periodontitis include a fiery red acute inflammation pervading the marginal and attached gingiva around all the teeth, gingival proliferation, cleft formation, and recession. Onset is at the time of tooth eruption. Alveolar bone destruction, sometimes accompanied by destruction of the tooth roots, proceeds at an alarming rate. The affected children have otitis media and recurrent, sometimes life‐threatening infections. Their periodontitis seems to be refractory to antibiotic therapy. In one case, the disease was controlled by extraction of the hopeless teeth combined with meticulous plaque control. Abnormalities in peripheral blood leukocyte chemotaxis have been found in all children with prepubertal periodontitis studied so far. In our children with the generalized form of the disease, both neutrophils and monocytes were profoundly abnormal and the basic defect appeared to be in cell adherence, while in children with localized disease, either neutrophils or monocytes but not both cell types were affected, and the defects were not profound. Prepubertal periodontitis seems to be more common in females than in males. In some families susceptibility appears to have a maternal pattern of inheritance, while in others no pattern of transmission is apparent. Prepubertal periodontitis may be followed by severe periodontitis of the permanent teeth or by a normal permanent dentition.

Efficient performance of the combination of treatment processes for oilfield produced water generated from oil tank dewatering was investigated in the study presented below. Byproduced wastewater is generated in significant quantity during exploitation of crude oil and gas from onshore and offshore production operations. This wastewater, commonly referred to as "produced water", has distinctive characteristics, due to their organic and inorganic compounds. However, these characteristics change from well to well. The treatment process investigated here consists of a pre-treatment step utilizing microfiltration (0.1 and 0.2µm pore size filters) and/or a simulated batch dissolved air flotation (DAF), and a multistage posttreatment step utilizing cross-flow ultra-(0.05µm pore size and 20kDa molecular weight cutoff filters), and nanofiltration (1 and 0.75kDa MWCO filters). Filters used were ceramic membranes. To determine the separation capability of the processes described, various parameters, such as trans-membrane pressure varying from 0.5 to 2 bar, cross-flow velocity in the range of 0.6 to 1.3m/s, influent oil concentration ranging from 32 to 5420 parts per million (ppm) and different membrane cleaning methods used were investigated. The average permeate flux varied from 3.4 to 3300 l/h*m²*bar, total oil removal was up to 99.5% and total organic carbon removal reached 49%.

Most patients with juvenile periodontitis manifest serum antibodies, sometimes at very high titers, to antigens of ActinobaciUus actinomycetemcomitans, but the antigens inducing the immune response have been only partly characterized. We separated A. actinomycetemcomitans serotype b cells into protein, lipopolysaccharide (LPS), and soluble polysaccharide fractions and characterized them. Coomassie blueand silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels were used to detect protein and LPS components, and gas-liquid chromatography was used to determine their carbohydrate and fatty acid composition. Western blots, dot blots, and enzyme-linked immunosorbent assay inhibition with high-titer sera from juvenile periodontitis patients revealed which components were highest in antibody binding activity. These results showed that the major portion of the immunoglobulin G binding activity resides in the purified mannan-free LPS, with lesser amounts in the total protein fraction. Using Sephacryl S-300 chromatography, we separated LPS into high-molecular-mass components with high carbohydrate contents by gas-liquid chromatography and a low-molecular-mass component consisting mainly of lipid A and the inner core sugar heptulose. The results of quantitative dot blot assays and enzyme-linked immunosorbent assay inhibition show that the serotype-specific antibody binding activity is highly concentrated in the high-molecular-mass carbohydrate-rich LPS fraction and is almost completely absent in the low-molecular-weight lipid-rich fraction. Our observations contrast with previous reports that the predominant serotype antigen of A. actinomycetemcomitans resides in a mannan-rich polysaccharide isolated from spent culture medium. These observations support the conclusion that the immunodominant antigen of the outer membrane is the 0 antigen of the LPS.

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We have assessed Macaca fascicularis as a potential model in which to test the efficacy and safety of a vaccine for periodontitis. Twenty-eight animals were surveyed and 20 studied in more detail. Clinical periodontal status was assessed, the subgingival microflora analyzed especially for the presence and proportions of Porphyromonas gingivalis and titers and avidities of serum antibodies reactive with P. gingivalis measured. Probing depths ranged from 0.90 mm to 3.80 mm, Gingival Index scores from 0.00 to 4.00 and Plaque Index scores from 0.00 to 3.00. About 40% of sites bled on probing. The animals manifested a subgingival flora characteristic of the anaerobic gram-negative bacteria found in human periodontal pockets, including Actinobacillus actinomycetemcomitans, P. gingivalis, Bacteroides forsythus, Campylobacter rectus, Prevotella intermedia and Fusobacterium nucleatum. P. gingivalis was detected in 70 of 80 samples studied, ranging from 0.01% to 20% of the total flora. Serum antibody reactive with antigens of P. gingivalis was observed in all animals, with titers ranging from 1.0 enzyme-linked immunosorbent assay (ELISA) unit to 25 ELISA units and avidities from 0.10 M to 2.20 M. Antibody titer and maximum percentage of P. gingivalis were inversely correlated, indicating that a humoral immune response may be effective in reducing P. gingivalis overgrowth. M. fascicularis appears to be an excellent model for use in vaccine development.