This memo describes DNS iterative resolver behavior that results in a significant query volume sent to the root and top-level domain (TLD) name servers.We offer implementation advice to iterative resolver developers to alleviate these unnecessary queries.The recommendations made in this document are a direct byproduct of observation and analysis of abnormal query traffic patterns seen at two of the thirteen root name servers and all thirteen com/net TLD name servers.
This study concerns the apical border (AB) plaque in relation to severe forms of periodontitis (SP), including juvenile, post-juvenile, and rapidly progressing periodontitis. Twenty-four (24) teeth from 16 patients with SP were examined by transmission electron microscopy (TEM). The AB was not discrete, with islands of bacteria in the so-called plaque-free zone (PFZ). Coronal to the AB the established plaque consisted of a layer of Gram-positive cocci and ghost cells and a superficial layer mainly of Gram-negative morphotypes, including cocci, rods, filaments, fusiforms, and spirochetes. The most apical apparently intact organisms in the PFZ were in bacterial islands or in isolation and were predominantly Gram-negative cocci and rods, with ghost cells in abundance. Ruthenium red, alcian blue-lanthanum nitrate, and safranin O were used to label matrix polyanionic macromolecules, and periodic acid (thiosemicarbazide) silver proteinate for intracellular polysaccharide (IPS). The matrix components were mainly fibrillar. Many intact bacteria exhibited extracellular polysaccharides or glycocalyces associated with their cell wall, and cytoplasmic IPS granules. The latter varied in distribution and were evident even in the most apically advanced intact microorganisms. The results indicate that IPS and some matrix features of the apical border plaque in severe periodontitis in certain aspects resemble those of sub-contact area plaque on children's teeth, in health or associated with early chronic gingivitis, and with those in chronic adult periodontitis. They also suggest the establishment of acidic regions in the microniche at the bottom of the periodontal pocket in the various forms of periodontitis differing in rate of progression. It was concluded that there was a limited range of intact bacterial morphotypes in the apical border plaque in severe periodontitis, similar to those in chronic adult periodontitis.
A study has been undertaken of the effects of a number of fixation procedures on the appearance of axons in the ureteric plexuses of the rat, and especially on the appearance of the dense-cored vesicles in those axons which have recently been characterized as pain afferents. Terminals were readily identified in material fixed by perfusion with glutaraldehyde, and many of them contained few if any vesicles. After fixation by immersion in cold glutaraldehyde terminals were not easy to identify because of the loss of microtubules. Immersion fixation in glutaraldehyde produced changes in the number and distribution of the vesicles in the axons which accentuated the similarity of the 'vesicle-containing regions' to the terminals of so-called 'purinergic' axons. Few of the dense-cored vesicles seen in glutaraldehyde-fixed material were preserved by fixation in permanganate, osmium or paraformaldehyde. The way dense-cored vesicles were or were not preserved by the various fixatives used indicated major differences between such cores and those of the vesicles in adrenergic axons. There was also evidence from the study of osmium-fixed material that both the number and appearance of the vesicles can be affected by the type of buffer used: the presence of more vesicles after fixation in osmium buffered with veronal than after osmium buffered in other ways was attributed to the membrane-stabilizing properties of veronal.
Abstract. This case report of severe periodontitis concerns a young male patient with chronic idiopathic neutropenia seen between 1981 and 1983 by the School of Dental Medicine of Geneva and from 1984 to 1988 by the Eastman Dental Hospital of London. The patient was maintained by intermittent systemic antibiotics, subgingival chlorhexidine irrigation, conventional debridement, brushing, and wire-mesh and composite splinting of loose teeth. After leaving school, at the patient's express wish, the extreme downhill pattern of the periodontitis resulted in removal of affected teeth and overdenture construction. The extracted teeth and associated soft tissues were examined for relevant plaque and host response features. The intact morphotypes associated with the advancing front of the lesion were invariably Gram-negative or positive coccoid cells, or less commonly short rods, as in all documented forms of periodotitis. Connective tissue destruction was associated with a leucocyte accumulation comprising mainly polymorphonuclear neutrophils (PMN) and plasma cells. Both were observed degenerated more deeply than in routine adult periodontitis, including PMN lysosome loss and lymphocyte maturation within peripheral blood vessels. Only in one instance, one part of the superficial connective tissue of one block contained bacteria. It was concluded that the features of plaque and the lesion suggest a typical first line of defence response as in other forms of periodontitis. From the consideration of the 10 years clinical history of the patient, it is clear that non-surgical management is possible even in extreme cases, without any compromise of the patient's oral or systemic health, and in accord with the patient's wishes.
The numbers of axons/unit length and of axons/group in the epithelium of the right and left sides of the trachea were determined in longitudinally orientated sections of specimens taken from five control rats, and from groups of five or six rats three days after section of the left vagus nerve above or below the nodose ganglion or section of the superior laryngeal and pharyngeal branches of the left vagus. After section of the vagus nerve below the nodose ganglion, there was a highly significant reduction in the number of axons/unit length in the epithelium of the ipsilateral side of the trachea, a significant reduction in the number of axons/group on this side and a small reduction in the number of axons/unit length on the contralateral side. The absence of similar changes in specimens from rats in which the vagus nerve was sectioned above the nodose ganglion, and in rats in which the branches from the ganglion were sectioned, indicated that the intraepithelial axons are derived from neurons whose perikarya are located in the ganglion and is consistent with the view that the axons are afferent. In addition to axons with terminals which resembled those which, in other tissues, have been defined as pain afferents, occasional axons with terminals containing numerous small clear vesicles were identified in the epithelium. The absence of these axons from the epithelium only in specimens taken from the ipsilateral side of the trachea after infranodose section of the left vagus nerve suggests that these may also be afferent.
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