Samples of apical plaque were taken by means of an anaerobic gas-flushed syringe from 21 sites in eight patients. The samples were anaerobically dispersed, diluted and plated and incubated in an atmosphere of 80% N2, 10% H2 and 10% CO2 for 7-21 days. All colonies on plates containing 20-50 isolates were picked, repeatedly restreaked, characterized and identified where possible by a probabilistic computer identification program. The sites were divided into four groups on the basis of clinical features. The significance of differences between bacterial populations in the groups was determined by the Kruskal Wallis and Mann-Whitney U tests, while the Spearman rank correlation coefficient was used to determine the rank correlation of clinical features of diseases and microbial species. The subgingival microbiota in advanced destructive sites was predominated by Gram-negative rods. The microbiota of two young adult patients with generalized extensive bone loss, extensive clinical inflammation and suppuration was dominated by Bacteroides asaccharolyticus and an organism with characteristics consistent with Actinobacillus actinomycetemcomitans. The predominant cultivable microbiota in two patients with extensive bone loss but minimal clinical inflammation was predominated by Bacteroides melaninogenicus ss intermedius and Eikenella corrodens in one patient and E. corrodens and a slow growing fusiform-shaped Bacteroides in a second patient. A third group of four patients demonstrated moderate levels of clinical inflammation and evidence of continued bone loss in the last year. Predominant organisms in this group were more heterogeneous and included B. asaccharolyticus, Fusobacterium nucleatum, the "fusiform" Bacteroides and anaerobic vibrios. Sites with minimal disease in the patients revealed higher proportions of Gram-positive organisms including Rothia dentocariosa, Actinomyces naeslundii and Actinomyces viscosus. A positive rank correlation could be detected between clinical inflammation including suppuration and B. asaccharolyticus and a negative rank correlation between inflammation and E. corrodens.

We compared 46 strains of gram-negative, asaccharolytic, rod-shaped bacteria which were isolated from humans with gingivitis, periodontal pockets, and lesions in alveolar bone with 10 reference strains of Eikenella corrodens, Vibrio succinogenes, Bacteroides ureolyticus, and species of Campylo bacter. We divided these 56 strains into seven groups based on the guanine-plus-cytosine contents of their deoxyribonucleic acids, their deoxyribonucleic acid homologies, and cluster analyses of their phenotypic features. A total of 23 of the fresh isolates showed more than 90% similarity (Jaccard coefficient) with E. corrodens. Growth of the remaining 23 isolates was enhanced in broth cultures by formate and fumarate.These isolates were not members of B. ureolyticus, V. succinogenes, or previously described species of Campylo bacter; they constituted three distinct new species. We propose Bacteroides gracilis sp. nov. (type strain, ATCC 33236) as the name for seven isolates of slender, gram-negative, nonmotile, anaerobic, rod-shaped bacteria that corroded agar and had deoxyribonucleic acid guanine-plus-cytosine contents of 44 to 46 mol%. All of the remaining isolates were motile by means of a single polar flagellum. Ten anaerobic strains were similar to V. succinogenes in phenotypic characteristics and guanine-plus-cytosine contents. However, these strains were distinct from V. succinogenes on the basis of deoxyribonucleic acid homology results. We propose Wolinella as the name of a new genus to include anaerobic, asaccharolytic, rod-shaped bacteria with single polar flagella and deoxyribonucleic acid guanine-plus-cytosine contents of 42 to 49 mol%. Wolinella succinogenes (Wolin et al.) comb. nov. is designated the type species of the genus, and ATCC 29543 is the type strain of W. succinogenes. We propose Wolinella recta sp. nov. (type strain, ATCC 33238) as the name for nine of the strains that formed a related but distinct group. We propose Campylobacter concisus sp. .nov. (type strain, ATCC 33237) as the name for the six isolates of noncorroding, microaerophilic, gram-negative, rod-shaped bacteria that have predominantly curved cells and deoxyribonucleic acid guanine-plus-cytosine contents of 34 to 38 mol%. The description of the genus Campylobacter is amended to include species with deoxyribonucleic acid guanine-plus-cytosine contents of 30 to 38 mol%.We isolated gram-negative, asaccharolytic, rod-shaped bacteria from humans with lesions of advanced destructive periodontal disease; the majority of these bacteria pitted or corroded agar media. These organisms were nonmotile, or they exhibited either cell "twitching" or active darting motility when they were examined by dark-field microscopy. These isolates were numerically dominant in some active disease sites (31). They were difficult to separate into distinct groups on the basis of routine characterization studies, and some of them were different from isolates of known species. In this investigation we compared strains isolated from humans with advanced periodontal d...

Major currently used anticancer therapeutics either directly damage DNA or target and upset basic cell division mechanisms like DNA replication and chromosome segregation. These insults elicit activation of cell cycle checkpoints, safeguard mechanisms that cells implement to correctly complete cell cycle phases, repair damage or eventually commit suicide in case damage is unrepairable. Although cancer cells appear to be advantageously defective in some aspects of checkpoint physiology, recent acquisitions on the biochemical mechanisms of the various checkpoints are offering new therapeutic approaches against cancer. Indeed, chemical manipulation of these mechanisms is providing new therapeutic strategies and tools to increase the killing efficacy of major cancer therapeutics as well as to directly promote cancer cell death. In this review we summarize developing concepts on how targeting cell cycle checkpoints may provide substantial improvement to cancer therapy.

Glucocorticoids are widely used in the therapy of inflammatory, autoimmune, and allergic diseases. As the end-effectors of the hypothalamic-pituitary-adrenal axis, endogenous glucocorticoids also play an important role in suppressing innate and cellular immune responses. Previous studies have indicated that glucocorticoids inhibit Th1 and enhance Th2 cytokine secretion. IL-12 promotes Th1 cell-mediated immunity, while IL-4 stimulates Th2 humoral-mediated immunity. Here, we examined the regulatory effect of glucocorticoids on key elements of IL-12 and IL-4 signaling. We first investigated the effect of dexamethasone on IL-12-inducible genes and showed that dexamethasone inhibited IL-12-induced IFN-γ secretion and IFN regulatory factor-1 expression in both NK and T cells. This occurred even though the level of expression of IL-12 receptors and IL-12-induced Janus kinase phosphorylation remained unaltered. However, dexamethasone markedly inhibited IL-12-induced phosphorylation of Stat4 without altering its expression. This was specific, as IL-4-induced Stat6 phosphorylation was not affected, and mediated by the glucocorticoid receptor, as it was antagonized by the glucocorticoid receptor antagonist RU486. Moreover, transfection experiments showed that dexamethasone reduced responsiveness to IL-12 through the inhibition of Stat4-dependent IFN regulatory factor-1 promoter activity. We conclude that blocking IL-12-induced Stat4 phosphorylation, without altering IL-4-induced Stat6 phosphorylation, appears to be a new suppressive action of glucocorticoids on the Th1 cellular immune response and may help explain the glucocorticoid-induced shift toward the Th2 humoral immune response.

Discovered during the past ten years, Janus kinases and signal transducers and activators of transcription have emerged as critical elements in cytokine signaling and immunoregulation. Recently, knockout mice for all the members of these families have been generated, with remarkably specific outcomes. Equally exciting is the discovery of a new class of inhibitors, the suppressor of cytokine signaling family. The phenotypes of mice deficient in these molecules are also striking, underscoring the importance of negative regulation in cytokine signaling.