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PubMedDate not supplied

Periodontal disease: an overview for physicians.

Periodontitis is now seen as resulting from a complex interplay of bacterial infection and host response, often modified by behavioral factors. There has been a fundamental change in the prevailing periodontal disease model of the 1960s, which suggested that the susceptibility to periodontitis increases with age, and that all individuals are susceptible to severe periodontal disease. More recent research has changed the belief in universal susceptibility to the current view that only some 5-20% of any population suffer from severe generalized periodontitis, and that only moderate disease affects a majority of adults. One major risk factor is smoking, as there is now a clear association between smoking and periodontal disease independent of oral hygiene, age, or any other risk factor. In human periodontitis, there is no simple, direct pathogen-disease link. There are three pathogens that have a strong association with progressive periodontal disease: Actinobacillus actinomycetemcomitans, spirochetes of acute necrotizing gingivitis, and Porphyromonas gingivalis. These pathogens may be the cause of continued loss of periodontal attachment in all periodontal disease classifications despite diligent periodontal therapy. This loss of attachment, or destruction of the periodontal ligament and loss of adjacent supporting bone, is seen in adult periodontitis, as well as in early-onset periodontitis, which affects young persons who otherwise appear healthy. The three forms of early-onset periodontitis are prepubertal periodontitis, localized and generalized juvenile periodontitis, and rapidly progressive periodontitis. They are distinguished from adult periodontitis by the age of onset of the disease, the rapid rate of disease progression, manifestations of defects in host response, and the composition of the subgingival microflora. Prepubertal periodontitis is associated with attachment loss around teeth of the deciduous and/or permanent dentition, and is often associated with severe congenital defects of hematological origin, and alterations in neutrophil chemotaxis function. Periodontitis may also be associated with systemic conditions such as metabolic disorders (diabetes mellitus, female hormonal alterations), drug-induced disorders, hematologic disorders/leukemia, and immune system disorders. These systemic disorders have been documented as capable of affecting the periodontium and/or treatment of periodontal disease. In order to rationally treat and prevent periodontal disease, we need to know the etiologic agents for specific patients, and the mechanism of bacterial pathogenesis in periodontitis. In systemic diseases in which the periodontal tissues are affected as well, early detection and carefully managed therapeutics with the physician and periodontist working together may prove beneficial to the patient's general health and quality of life.

Adult↗

PubMed2006

Angioedema without urticaria: a large clinical survey.

BACKGROUND: Angioedema without major urticarial flares (hives) is poorly understood. Its causes are diverse, and little is known about its pathogenic mechanisms. We report on our 11 years of experience with this condition and propose a classification of patients affected by angioedema unaccompanied by urticaria. METHODS: From 1993 through 2003 at our outpatient clinic, 929 consecutive patients were examined for recurrent angioedema unaccompanied by urticaria. A detailed history was taken to identify known causes of angioedema, with special attention to external allergenic agents. Each patient underwent a complete physical examination, routine laboratory tests (blood cell count, protein electrophoresis, erythrosedimentation rate, examination of stool for ova and parasites, pharyngeal and urine cultures, sinus and dental radiography, and measurements of antitissue autoantibodies and rheumatoid factor in plasma), and complement parameters (C1 inhibitor, C4 and C1q). Further testing was done when pertinent, based on clinical findings. When all results were negative, response to H1-antihistamine was considered. RESULTS: Angioedema could not be classified in 153 patients who were lost to follow-up (16.4%). Among the 776 cases with adequate data, these types of angioedema were identified: 124 (16%) related to external agents such as a drug, insect bite or foodstuff; 85 (11%) related to treatment with angiotensin-converting enzyme inhibitor; 55 (7%) associated with an autoimmune disease or infection; and 197 (25%) caused by C1 inhibitor deficiency. In the other 315 cases (41%), the etiology was undiscovered: 254 cases (33% of the study sample) were idiopathic histaminergic; 40 (5%) were idiopathic nonhistaminergic; and 21 (3%) had other causes of peripheral or generalyzed edema. INTERPRETATION: Our data indicated that angioedema without urticaria could be classified according to specific clinical and pathogenic characteristics, and we have suggested a work-up for patients experiencing this condition.

Adolescent↗

PubMed1994

Community-acquired pneumonia: the future of the microbiology laboratory: focused diagnosis or syndromic management?

The traditional classification of community-acquired pneumonia into typical and atypical pneumonia to facilitate successful empirical treatment is no longer optimal. An accurate prediction of cause and adequate empirical therapy cannot be provided with this approach in severely ill patients. There is an increasing spectrum of recognized treatable pathogens presenting as community-acquired pneumonia including Legionella species, Chlamydia pneumoniae, and Pneumocystis carinii in addition to the traditional community pathogens. The variability of presentation in severely ill or compromised hosts makes clinical prediction of cause inadequate. A more rational approach may involve the classification of patients by the severity of illness and underlying disease with little or no microbiological workup in mild illness unless the results will contribute to the epidemiological surveillance of resistance because these investigations have not been shown to affect outcome in this setting. Etiologic diagnosis should be more aggressively sought and the microbiology laboratory can be best used by providing the efficient and rapid diagnosis of this expanded range of pathogens in more severely ill patients. The mounting antimicrobial resistance of common pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus will require not only a critical review of empirical therapy, but an increased emphasis on epidemiological monitoring of resistance by laboratories and effective communication with clinicians.

Bacteria↗

PubMed2006

Genomic structure and phylogeny of the plant pathogen Ralstonia solanacearum inferred from gene distribution analysis.

In the present study, we investigated the gene distribution among strains of the highly polymorphic plant pathogenic beta-proteobacterium Ralstonia solanacearum, paying particular attention to the status of known or candidate pathogenicity genes. Based on the use of comparative genomic hybridization on a pangenomic microarray for the GMI1000 reference strain, we have defined the conditions that allowed comparison of the repertoires of genes among a collection of 18 strains that are representative of the biodiversity of the R. solanacearum species. This identified a list of 2,690 core genes present in all tested strains. As a corollary, a list of 2,338 variable genes within the R. solanacearum species has been defined. The hierarchical clustering based on the distribution of variable genes is fully consistent with the phylotype classification that was previously defined from the nucleotide sequence analysis of four genes. The presence of numerous pathogenicity-related genes in the core genome indicates that R. solanacearum is an ancestral pathogen. The results establish the long coevolution of the two replicons that constitute the bacterial genome. We also demonstrate the clustering of variable genes in genomic islands. Most genomic islands are included in regions with an alternative codon usage, suggesting that they originate from acquisition of foreign genes through lateral gene transfers. Other genomic islands correspond to genes that have the same base composition as core genes, suggesting that they either might be ancestral genes lost by deletion in certain strains or might originate from horizontal gene transfers.

Chromosome Mapping↗

PubMed1985

The classification of Sejroe group serovars of Leptospira interrogans with monoclonal antibodies.

Using the hybridoma technique we produced monoclonal antibodies to serovars of Leptospira interrogans. We focussed on serovar hardjo which is an important pathogen for humans and animals, and on other serovars of the Sejroe group. With combinations of monoclonals, characteristic patterns of agglutination were observed according to the specific pattern of antigenic determinants of that serovar. A set of 13 monoclonal antibodies was composed which allowed the classification of almost all serovars of the Sejroe group.

Agglutination Tests↗

PubMed1988

[Pathogenic concepts, nosological limits and diagnostic criteria of Behçet's disease].

Behçet's disease, a multi-system disease, raises aetiological and classification problems. Its aetiology is unknown, although several factors have been incriminated in its pathogenesis: immunogenetic, toxic, viral, hormonal,... It overlaps with several groups of diseases: seronegative spondyloarthritis, connective tissue diseases, angiitis, uveomeningitis and aphthosis. Several diagnostic criteria proposed by various authors are discussed.

Behcet Syndrome↗

PubMed2005

Pharmacodynamic analysis of the microbiological efficacy of telithromycin in patients with community-acquired pneumonia.

BACKGROUND AND OBJECTIVE: Telithromycin, a ketolide antibacterial, demonstrates concentration-dependent bactericidal activity against the major pathogens causing community-acquired respiratory tract infections. The objective of this study was to explore the relationships between pharmacokinetic/pharmacodynamic predictor variables, such as area under the plasma concentration-time curve (AUC) over minimum inhibitory concentration (MIC) [AUC/MIC], maximum plasma concentration (C(max)) over MIC (C(max)/MIC) and microbiological outcome from telithromycin therapy for community-acquired pneumonia (CAP). PATIENTS AND METHODS: Data were pooled from five phase III studies of oral telithromycin (800 mg once daily for 7-10 days) for the outpatient treatment of adults with CAP. Only subjects with a single pathogen isolated at baseline, a telithromycin MIC determination and at least one plasma pharmacokinetic sample were included. Bacteriologically modified intent-to-treat (bmITT) and bacteriologically evaluable per protocol (PPb) populations were analysed. Individual AUC and C(max) Bayesian estimates were obtained with a population pharmacokinetic model. Logistic regression, nonparametric smoothing, and classification analysis and regression tree (CART) were used to assess the relationship between AUC/MIC and C(max)/MIC and microbiological outcome by pathogen. RESULTS: The bmITT population included 224 patients (Streptococcus pneumoniae in 113, Haemophilus influenzae in 89 and Staphylococcus aureus in 22). Median telithromycin MIC was 0.015 microg/mL for S. pneumoniae, 2.0 microg/mL for H. influenzae and 0.12 microg/mL for S. aureus, with median AUC/MIC of 907.1, 6.9 and 98.4, and median C(max)/MIC of 172.0, 1.3 and 20.4 for the three pathogens, respectively. Both logistic regression and nonparametric smoothing showed the probability of microbiological cure to be consistently greater than 90% over the observed range of predictor variables. No reliable AUC/MIC or C(max)/MIC breakpoints were identified by CART. CONCLUSION: Telithromycin exhibits near-maximal efficacy against three major pathogens causing CAP at a dose of 800 mg once daily.

Adolescent↗

PubMed2004

Indicators of potentially drug-resistant bacteria in severe nursing home-acquired pneumonia.

BACKGROUND: Knowledge of the determinant factors responsible for the presence of antimicrobial-resistant pathogens in severe nursing home-acquired pneumonia (NHAP) is deemed essential for antibiotic selection. METHODS: Data for institutionalized patients with cases of severe pneumonia confirmed by culture of protected bronchoalveolar lavage fluid samples (> or =10(3) cfu/mL) during a 36-month period were analyzed. A classification tree with a sensitivity of 100% was developed using binary recursive partitioning to predict which patients are unlikely to have drug-resistant pathogen (DRP)-related pneumonia. RESULTS: Of the 88 patients who satisfied the inclusion criteria, 17 had at least 1 DRP recovered from the lower respiratory tract. The predictor variables were the Activity of Daily Living score and previous use of antibiotics. Prospective application of the model in 47 patients over a 24-month period yielded a sensitivity of 100% (95% confidence interval [CI], 71.3%-100%) and a specificity of 69.4% (95% CI, 51.9%-83.6%). CONCLUSIONS: The use of the tree may provide a more rational basis for selecting initial therapy for severe NHAP after it is validated in a large prospective study.

Aged↗

PubMed2025

The ClinGen Severe Combined Immunodeficiency Disease Variant Curation Expert Panel: Specifications for classification of variants in ADA, DCLRE1C, IL2RG, IL7R, JAK3, RAG1, and RAG2.

PURPOSE: This collaborative study, led by the Clinical Genome Resource Severe Combined Immunodeficiency Disease Variant Curation Expert Panel (ClinGen SCID-VCEP), implemented and adapted the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines for interpreting germline variants in genes with established relationships to SCID. The effort focused on the 7 most common SCID-related genes identified by SCID newborn screening in North America: ADA, DCLRE1C, IL2RG, IL7R, JAK3, RAG1, and RAG2. METHODS: The SCID-VCEP conducted a rigorous review of variants that involved database analyses, literature review, and expert feedback to derive gene-specific modifications to the ACMG/AMP guidelines. These specifications were validated using a pilot set of 90 variants. RESULTS: Of these 90 variants, 25 were classified as pathogenic, 21 as likely pathogenic, 14 as variants of uncertain significance, 18 as likely benign, and 12 as benign. Seventeen variants with conflicting classifications in ClinVar were successfully resolved. The criteria included modifications to 20 of the 28 original ACMG/AMP criteria specific to SCID-related genes. CONCLUSION: The SCID-specific variant curation guidelines developed by the SCID-VCEP will enhance the precision of SCID genetic diagnosis and provide a robust framework for interpreting variants in SCID-related genes, contributing to appropriate treatment of SCID.

Humans↗

PubMed2005

The Microbial Rosetta Stone Database: a compilation of global and emerging infectious microorganisms and bioterrorist threat agents.

BACKGROUND: Thousands of different microorganisms affect the health, safety, and economic stability of populations. Many different medical and governmental organizations have created lists of the pathogenic microorganisms relevant to their missions; however, the nomenclature for biological agents on these lists and pathogens described in the literature is inexact. This ambiguity can be a significant block to effective communication among the diverse communities that must deal with epidemics or bioterrorist attacks. RESULTS: We have developed a database known as the Microbial Rosetta Stone. The database relates microorganism names, taxonomic classifications, diseases, specific detection and treatment protocols, and relevant literature. The database structure facilitates linkage to public genomic databases. This paper focuses on the information in the database for pathogens that impact global public health, emerging infectious organisms, and bioterrorist threat agents. CONCLUSION: The Microbial Rosetta Stone is available at http://www.microbialrosettastone.com/. The database provides public access to up-to-date taxonomic classifications of organisms that cause human diseases, improves the consistency of nomenclature in disease reporting, and provides useful links between different public genomic and public health databases.

Animals↗

PubMed1999

Periodontitis.

The purpose of this review was to assess the scientific and clinical bases for the proposed classification of periodontitis. The clinical and histopathological signs and the etiology of periodontitis were described. Cross-sectional studies were analyzed to determine when onset of periodontitis most frequently occurs in adults. In addition, the progression rates of periodontitis have been assessed from longitudinal studies. No clinical, histopathological, or microbiological features could be identified that would characterize different disease entities of chronic periodontitis. The prevalence, extent, and severity of periodontitis were found to increase continually with higher age and there was no age when onset of disease would most likely occur. The rate of periodontitis progression varies largely between patients and there is no natural threshold for distinguishing various rates of disease progression. The incidence of periodontitis unresponsive to treatment depends on pretreatment progression rate, extent and severity of disease, tooth type, smoking, high levels of putative periodontal pathogens, a deficient immune response, and the type of therapy provided. There is no scientific basis for the classification "adult periodontitis" and "refractory adult periodontitis." Extensive clinical examinations are required for the diagnosis of "rapidly progressive adult periodontitis." It appears unrealistic that these examinations can be performed routinely in clinical practice. Therefore, the classification proposed by the Organizing Committee to define adult, rapidly progressive, and refractory periodontitis as specific disease entities was replaced with a simplified classification of periodontitis based on the scientific data available.

Acute Disease↗

PubMed1976

Mycobacterium fortuitum mastoiditis.

Improved techniques of bacteriologic identification have led to increasing recognition of the clinical significance of the atypical or anomymous mycobacteria. Mycobacterium fortuitum, included in group IV of Runyon's classification because of its characteristic rapid growth, is widespread in nature as a saprophyte. Its facultative pathogenicity has received increasing attention in the literature recently with reports of a number of isolated infections, epidemics, and deaths. We report a case of mastoiditis due to M fortuitum and discuss the pathogenesis and treatment. This is the first known report of the organism causing otolaryngologic disease.

Atypical Bacterial Forms↗

PubMed1987

Serum antibodies and monoclonal antibodies secreted by thymic B-cell clones from patients with myasthenia gravis define striational antigens.

The biochemical identities of several antigens to which striational antibodies bind were determined by using serum antibodies and monoclonal antibodies from two patients with myasthenia gravis. The monoclonal antibodies were secreted by EBV-transformed B-lymphocyte clones obtained from thymus and thymoma. Serum and monoclonal antibodies reacted with discrete components of the skeletal muscle sarcomere, giving rise to several different patterns of immunofluorescence staining. Immunoblot analyses and enzyme-linked immunosorbent assays revealed three different antibody specificities: myosin, alpha-actinin, and/or actin. Individual monoclonal StrAb reacted with both muscle and nonmuscle isotypes of actin or myosin. It is noteworthy that contractile proteins (1) are associated with acetylcholine receptors (AChR) in plasma membranes, and (2) are biochemically altered in transformed cells. It is therefore conceivable that the release of neoantigenic AChR-associated contractile proteins from thymic epithelial cells undergoing neoplastic transformation may provide the immunogenic stimulus for production of StrAb. More precise definition of StrAb specificities in individual patients with MG and/or thymoma might provide a basis for diagnostic and/or prognostic classification of these diseases. Furthermore, the monoclonal antibodies will be useful in experimentally testing the potential pathogenicity of StrAb.

Actinin↗

PubMed1988

Outcome of untreated infection with Entamoeba histolytica in homosexual men with and without HIV antibody.

Among homosexual men the prevalence of infection with Entamoeba histolytica is high. To determine the clinical importance of this infection 55 homosexual men carrying the parasite were investigated in detail. No clinical, serological, or histological evidence of invasive amoebiasis was found in any of them. The patients were not treated and were followed up for 12 to 29 months (mean 21.6 months), during which period none developed symptoms that could be attributed to E histolytica. Spontaneous loss of the parasite occurred in 17 patients, some of whom later became reinfected. Sixteen patients had antibody to human immunodeficiency virus, and infection with E histolytica showed the same benign course in them as in the patients who did not have antibody. Throughout the study classification of the isolates of E histolytica consistently showed that they belonged only to non-pathogenic zymodemes. The findings provide further evidence that E histolytica in homosexual men is a commensal organism.

Animals↗

PubMed2004

Expression profiling of T-cell lymphomas differentiates peripheral and lymphoblastic lymphomas and defines survival related genes.

PURPOSE: T-Cell lymphomas constitute heterogeneous and aggressive tumors in which pathogenic alterations remain largely unknown. Expression profiling has demonstrated to be a useful tool for molecular classification of tumors. EXPERIMENTAL DESIGN: Using DNA microarrays (CNIO-OncoChip) containing 6386 cancer-related genes, we established the expression profiling of T-cell lymphomas and compared them to normal lymphocytes and lymph nodes. RESULTS: We found significant differences between the peripheral and lymphoblastic T-cell lymphomas, which include a deregulation of nuclear factor-kappaB signaling pathway. We also identify differentially expressed genes between peripheral T-cell lymphoma tumors and normal T lymphocytes or reactive lymph nodes, which could represent candidate tumor markers of these lymphomas. Additionally, a close relationship between genes associated to survival and those that differentiate among the stages of disease and responses to therapy was found. CONCLUSIONS: Our results reflect the value of gene expression profiling to gain insight about the molecular alterations involved in the pathogenesis of T-cell lymphomas.

Cell Survival↗

PubMed1991

[Histologic classification of HIV-1 induced lymphadenopathy. Current results on the pathogenesis of germinal center changes].

At the IV International Conference on AIDS in Stockholm, a Symposium on the pathology of HIV-related diseases was organized. During this Symposium the "European Study Group on HIV-Pathology" presented a histological classification of lymph node alterations seen in HIV-associated lymphadenopathy. The goal of the Study group was to offer a common terminology for histologic changes previously described with different terms by different authors. In the present review the most important histological criteria used in the proposed classification are summarized. Since the classification is based on the conspicuous changes of the follicles, a brief review of the possible pathogenic mechanisms leading to disintegration of the germinal centers will also be given.

AIDS-Related Complex↗

PubMed1993

Classification of a new member of the TBE flavivirus subgroup by its immunological, pathogenetic and molecular characteristics: identification of subgroup-specific pentapeptides.

The antigenic, pathogenic and molecular characteristics of Turkish sheep encephalitis (TSE) virus, strain TTE80, were compared with other members of the tick-borne encephalitis (TBE) virus complex. Monoclonal antibodies with defined specificity for the flavivirus envelope glycoprotein distinguished TSE virus from louping ill (LI), western or far eastern TBE, Langat and Powassan virus in indirect immunofluorescence, haemagglutination-inhibition and neutralization tests. On the other hand, TSE virus, which produces an LI-like disease in sheep, resembled LI virus in mouse neurovirulence tests. Molecular homology data of all the structural genes of TSE virus compared with other tick-borne flaviviruses demonstrated that TSE virus is a distinct member in the TBE virus subgroup. The data are consistent with the conclusion that TSE virus has evolved by a separate evolutionary pathway as compared with the close antigenic relatives, western European, far eastern TBE viruses and LI virus. By aligning the encoded amino acids in the viral envelope glycoprotein of mosquito- and tick-borne flaviviruses, we have also identified subgroup-specific pentapeptide motifs for the tick-borne encephalitis, Japanese encephalitis and dengue subgroup viruses of the genus Flavivirus. These pentapeptides have important implications for the evolution, classification and diagnosis of flaviviruses.

Amino Acid Sequence↗

PubMed2003

[Classification of Fungi in modern view].

Fungi are a heterogeneous jumble coming together from three kingdoms of organisms. The True Fungi represent a kingdom of its own and are positioned closer to the Animalia than to the Plantae. At present the Fungi are divided into five Divisions. Species pathogenic for humans are found in the Divisions Zygomycota, Ascomycota and Basidiomycota. The Pneumocystidales are now classified in the Ascomycota. The Malasseziales are included in the Class Ustilaginomycetes. Essential characteristics for the classification of Fungi are derived from ultrastructure, chemistry, and more recently also from molecular biology of these organisms. None of these methods can stand for its own, all characteristics must be included.

Classification↗