SEARCH · Search PubMed

Results for “pathogenicity classification”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources

PubMed1986

Classification of Histoplasma capsulatum isolates by restriction fragment polymorphisms.

Twenty isolates of the dimorphic, pathogenic fungus Histoplasma capsulatum were divided into three classes based on comparisons of restriction enzyme digests of their mitochondrial DNA and rDNA. The majority of isolates, including most North American strains and the African H. capsulatum var. duboisii variants, belong to class 2. Isolates from Central America and South America make up class 3. The attenuated Downs strain is the only member of class 1.

Africa↗

PubMed2003

Analysis and functional classification of transcripts from the nematode Meloidogyne incognita.

BACKGROUND: Plant parasitic nematodes are major pathogens of most crops. Molecular characterization of these species as well as the development of new techniques for control can benefit from genomic approaches. As an entrée to characterizing plant parasitic nematode genomes, we analyzed 5,700 expressed sequence tags (ESTs) from second-stage larvae (L2) of the root-knot nematode Meloidogyne incognita. RESULTS: From these, 1,625 EST clusters were formed and classified by function using the Gene Ontology (GO) hierarchy and the Kyoto KEGG database. L2 larvae, which represent the infective stage of the life cycle before plant invasion, express a diverse array of ligand-binding proteins and abundant cytoskeletal proteins. L2 are structurally similar to Caenorhabditis elegans dauer larva and the presence of transcripts encoding glyoxylate pathway enzymes in the M. incognita clusters suggests that root-knot nematode larvae metabolize lipid stores while in search of a host. Homology to other species was observed in 79% of translated cluster sequences, with the C. elegans genome providing more information than any other source. In addition to identifying putative nematode-specific and Tylenchida-specific genes, sequencing revealed previously uncharacterized horizontal gene transfer candidates in Meloidogyne with high identity to rhizobacterial genes including homologs of nodL acetyltransferase and novel cellulases. CONCLUSIONS: With sequencing from plant parasitic nematodes accelerating, the approaches to transcript characterization described here can be applied to more extensive datasets and also provide a foundation for more complex genome analyses.

Animals↗

PubMed1980

[Basic types of pathogenic infections].

The theory of the pathogenetic basic types renders possible a clinical basic classification of the infectious diseases. The essential qualities and characteristics of the cyclic infectious diseases, of the local infections and of sepsis are again represented in a survey and explained in the light of more recent knowledge.

Humans↗

PubMed1996

[Changes in the taxonomy and nomenclature of pathogenic microscopic fungi].

The authors present a survey of medically important microscopic fungi whose classification were critically revised and correctly named in the last few years. The list was adopted from a paper of American mycologists trying to make the nomenclature of mycotic agents more precise and stable. The authors divided the adopted list according to diseases the individual fungi produce and explained less known terms describing mostly non-european mycoses. Notes giving reasons for nomenclature changes supplement the list of names.

Classification↗

PubMed1986

Conidiogenesis of fungi pathogenic for man.

Despite an apparent stabilizing of nomenclature and concepts involved in fungal conidiogenesis during the past decade, there is now evidence that a much more complex and demanding approach to the descriptive study of processes involved in conidial formation would allow a more phylogenetically realistic classification of anamorphic fungi. The present review attempts to evaluate data on the human pathogenic molds in light of this new approach and to relate conidiogenesis to the known teleomorph connections of the fungi concerned. It is hoped that by treating the species in groups corresponding to their sexual affinities, it may be possible to infer homologous forms of conidiogenesis by comparative morphology and development.

Arthrodermataceae↗

PubMed2025

Uveal Melanoma and the Lynch Syndrome Tumor Spectrum.

IMPORTANCE: To date, no environmental factors and few therapeutic options are known for uveal melanoma (UM), the most common malignant intraocular primary tumor in adults. Identification of new predisposition factors could lead to better monitoring and possibly improved treatments of patients with UM. OBJECTIVE: To identify new genetic alterations predisposing for UM. DESIGN, SETTING, AND PARTICIPANTS: This was a prospective cohort study conducted at Institut Curie in Paris, France, among 381 consecutive patients diagnosed with UM between July 2021 and February 2023. UM was diagnosed clinically by ophthalmologists, and a senior pathologist confirmed the diagnosis when tumor or biopsy was available. All participants received genetic counseling and consented to extended genetic testing. A panel of 122 genes predisposing to cancer were analyzed by targeted sequencing on germline DNA from these patients. MAIN OUTCOMES AND MEASURES: Frequency of pathogenic variants (PVs) in genes from a targeted panel, with classification of germline PVs done according to the American College of Medical Genetics and Genomics guidelines and the French Unicancer Genetics Group. RESULTS: A total of 79 PVs were identified in 70 participants (41 female and 29 male; mean [SD] age, 60.6 [15.3] years). Among them, 21 were found in clinically relevant genes, with an enrichment in the mismatch repair (MMR) genes, involved in Lynch syndrome, a frequent predisposition to colon and endometrial cancers. This finding suggested MMR germline PVs could also predispose to UM. One tumor was available from a participant carrying a MLH1 germline PV. The tumor exhibited a monosomy 3 with loss of the wild-type allele of MLH1, located on chromosome 3. Loss of expression of MLH1 was observed by immunohistochemistry, and MMR variant signatures SBS6, ID1, and ID2 were identified from the whole-genome sequencing of this tumor, supporting the possibility that MLH1 contributes to the oncogenesis of this UM. CONCLUSIONS AND RELEVANCE: This prospective germline study on patients with UM provided evidence supporting the notion that MMR germline alterations are enriched among patients with UM and may contribute to oncogenesis of UM, and that UM may therefore be a rare tumor manifestation of Lynch syndrome.

Humans↗

PubMed1975

Envelope proteins in Neisseria.

The proteins of the cell envelope of Neisseria sicca strain ATCC 9913 have been examined by SDS - polyacrylamide gel electrophoresis. Some 20 proteins were resolved from the total envelope fraction, and nearly all of these were found to be localized in the outer membrane. Preparations of the "free-endotoxin" fraction differ from the outer membrane only in lacking a few minor proteins. The behavior of several of the envelope proteins on electrophoresis can be modified by changing the temperature of sample solubilization, and also by alteration of the growth medium. Experiments with phosphate-limited cultures showed that certain periplasmic proteins are closely associated with free endotoxin. Mutations which result in altered outer membrane permeability to antibiotics were found to cause changes in cell envelope protein composition. A comparison of the envelope proteins of eight species of non-pathogenic Neisseria showed that each had a characteristic composition. A classification of the organisms based on the relatedness of the protein patterns seen on SDS-polyacrylamide gels was in close agreement with classifications based on more usual methods.

Anti-Bacterial Agents↗

PubMed2001

What do we really know about antibiotic pharmacodynamics?

Antibiotic pharmacodynamics is an evolving science that focuses on the relationship between drug concentration and pharmacologic effect, which is an antibiotic-induced bacterial death that also can manifest as an adverse drug reaction. The pharmacologic action of antibiotics usually can be described as concentration dependent or independent, although such classifications are highly reliant on the specific antibiotic and bacterial pathogen being studied. Quantitative pharmacodynamic parameters, such as ratio of the area under the concentration-time curve during a 24-hour dosing period to minimum inhibitory concentration (AUC0-24:MIC), ratio of maximum serum antibiotic concentration to MIC (Cmax:MIC), and duration of time that antibiotic concentrations exceed MIC (T>MIC), have been proposed as likely predictors of clinical and microbiologic success or failure for different pairings of antibiotic and bacteria. Thus far, most pharmacodynamic data reported have focused on fluoroquinolones, but work has been conducted on vancomycin, beta-lactams, macrolides, aminoglycosides, and other antibiotics. Despite the development of a number of different pharmacodynamic modeling systems, remarkable agreement exists between in vitro, animal, and limited human data. Although still somewhat premature and requiring additional clinical validation, antibiotic pharmacodynamics will likely advance on four fronts: the science should prove to be extremely useful and represent a cost-effective and efficient method to help develop new antibiotics; formulary committees will likely use pharmacodynamic parameters to assist in differentiating antibiotics of the same chemical class in making antibiotic formulary selections; pharmacodynamic principles will likely be used to design optimal antibiotic strategies for patients with severe infections; and limited data to date suggest that the application of pharmacodynamic concepts may limit or prevent the development of antibiotic resistance. The study of antibiotic pharmacodynamics appears to hold great promise and will likely become a routine part of our daily clinical practices.

Animals↗

PubMedDate not supplied

Idiopathic hypercalciuria: effects of calcium load test on magnesiuria.

Twenty-three children with idiopathic hypercalciuria and 7 control children were studied. Patients were classified into three groups according to the response to an oral calcium load. Five children displayed absorptive hypercalciuria (UCa/Cr 0.14 +/- 0.04 mg/mg with poor calcium diet and 0.33 +/- 0.16 after loading, p less than 0.01); 10 were classified renal hypercalciuria (UCa/Cr during the fasting state of 0.28 +/- 0.09 and 0.31 +/- 0.11 after loading) and 8 were classified as alimentary hypercalciuria (UCa/Cr 0.14 +/- 0.07 during the fasting state and 0.15 +/- 0.04 after loading). The urinary cAMP showed no significant differences in any of the three groups compared to the control. Magnesiuria did not show significant differences between the two forms of hypercalciuria and the control; a significant increase was observed after the loading and a positive correlation between magnesiuria and calciuria in the absorptive form. Our study supports the validity of the test for the classification of the different forms of hypercalciuria in children. The urinary cAMP is not a valid approach for classification. The difference observed in the magnesiuria suggests a different pathogenic mechanism between the two types of idiopathic hypercalciuria.

Administration, Oral↗

PubMed1985

[Interpretation of the cell concentration of cow's milk for the diagnosis of mammary infection].

The potential utilisation of monthly cell counts per cow to determine their infection status was studied for 30 months on 62 cows from an experimental herd, and by simulation, on different herd models with defined epidemiological characteristics. During this period, the cows of the experimental herd were regularly submitted to bacteriological tests for intramammary infections and individual cell counts. The cows which were not chronically infected by a major pathogen were characterised by cell counts of less than 300 000 cells/ml throughout lactation. The chronically infected cows were characterised by at least two peaks over 300 000 with at least one beyond 800 000, but cell counts could be, at other time intervals, below 300 000 cells/ml. Provided that at least two monthly cell counts were available for each cow, it was possible to discriminate strongly the cows not chronically infected and the cows chronically infected by a major pathogen which are reservoirs of infection. The percentage of correct classifications varied between 74 and 87% in relation with the chosen threshold and the infection status of the herd in which this threshold was used. With the same threshold, there were higher percentages of false negative diagnosis in a herd model where staphylococcal like long-term infections were prevalent and of false positive when there was a high incidence of clinical short-term infections. Monthly cell counts per cow did not correctly reveal short-term clinical infections which are particularly prevalent in herds affected mainly by environmental mastitis. The precision and practical importance of this individual diagnosis was discussed for different herd models.

Animals↗

PubMed1998

Biosafety considerations in handling medically important fungi.

Over 500,000 workers in the USA alone are employed in laboratories that range from small physician offices to large clinical laboratories handling microbes for comprehensive research and/or diagnostic work. These workers are exposed to a variety of potential occupational health risks such as exposure to infectious clinical materials, environmental specimens, cultures, complex and inflammable chemicals, radiation, and electrical and mechanical hazards. As members of the International Society for Human and Animal Mycology, we have no policy statement on biosafety standards for handling medically important fungi. The intent of the symposium is to cover some of the important aspects of biosafety; (1) standards in handling dimorphic fungal pathogens; (2) the principles and criteria of biosafety levels and classification of known medically important fungi, aerobic actinomycetes, environmental fungi according to their biosafety levels; (3) medically important fungal waste and its safe disposal; and (4) biosafety and regulatory considerations in handling and mailing medically important fungi in a culture collection.

Animals↗

PubMed2002

Apoptosis in lymphocytic leukemias and lymphomas.

Most current classifications of lymphoid neoplasms define the tumors based on the cell of origin, phenotype, genetic abnormalities, and clinical features. Here it is proposed that human lymphocytic tumors can be categorized based on the propensity and capacity of the tumor cells to undergo apoptosis. The first category is defined by malignant cells that are resistant to apoptosis due to expression of anti-apoptotic factors such as bcl-2 and cellular inhibitors of apoptosis (IAPs). These tumors would include CLL and follicular lymphomas, as well as some malignancies in which the tumor cells are infected by viruses that co-opt cell survival pathways, such as human T-cell leukemia/lymphoma virus (HTLV)-1. The second category, in which the malignant cells are apoptosis-prone, would include tumors arising in the context of impaired cytotoxic T-cell function. These neoplasms would include some human immunodeficiency virus (HIV)-related lymphomas such as Burkitt's lymphoma, and post-transplantation lymphomas. The third category would include neoplasms of intermediate sensitivity to apoptosis, some of which are associated with infection such as mucosa-associated lymphoid tissue (MALT) lymphomas of the stomach. Although this classification is tentative, it should evolve in parallel with our understanding of pathogenic mechanisms in lymphoid neoplasia, and provides a novel framework with which to consider the appropriateness of specific therapeutic strategies. Distinctions among lymphocytic tumors in terms of the likelihood of response to therapies such as antisense to bcl-2 related proteins, inhibitors of NF-kappa B activity, and new approaches aimed at bolstering the host's immune response, would cross standard classifications based on the T or B-cell origin of the tumor cells.

Apoptosis↗

PubMed1962

Acetylmethylcarbinol production and the classification of aeromonads associated with ulcerative diseases of ectothermic vertebrates.

Page, L. A. (Biological Research Institute, San Diego, and University of California, Davis). Acetylmethylcarbinol production and the classification of aeromonads associated with ulcerative diseases of ectothermic vertebrates. J. Bacteriol. 84:772-777. 1962.-Quantitative colorimetric tests were made for acetylmethylcarbinol (AMC) production by 14 Aeromonas isolates from ulcerous lesions of snakes, lizards, frogs, and other animals, and by 27 cultures of "identified" aeromonads. The tests revealed that: (i) some strains failed to produce AMC, while the other strains produced AMC in amounts of 5 to > 100 mug/ml of culture; (ii) the reagents employed in the standard method of Barritt failed to detect AMC in concentrations below 35 mug/ml; and (iii) certain strains reported as producing AMC at 23 C and not at 37 C (or vice versa) produced AMC at both temperatures, but at one temperature produced AMC at a level below the sensitivity of the qualitative test. The strains representing the two biotypes could not be distinguished on the basis of their morphology, habitat, pathogenicity for mice or snakes, or serological specificity. Therefore, the Aeromonas classification proposed by Ewing, Hugh, and Johnson, who incorporated the two biotypes into one species, was followed, and the new isolates were designated A. hydrophila.

Acetoin↗

PubMed2002

Idiopathic inflammatory myopathies - myositis.

The inflammatory myopathies - myositis - encompass a heterogeneous group of chronic muscle disorders of unknown origin and with varying prognoses. New clinical phenotypes of myositis have been identified since the most widely used classification criteria were proposed in 1975. Based on clinical and histopathological features, inclusion body myositis was identified. Furthermore, the myositis-specific autoantibodies may also identify different clinical phenotypes and serve as prognostic markers. The different classifications and inclusion criteria that have been used in different studies make some epidemiological data uncertain. In order to improve our knowledge of causative factors, as well as of pathogenic mechanisms, there is a need for revision and also for an international acceptance of the classification criteria. During recent years, our knowledge has increased regarding the role of some genetic and environmental factors that could affect susceptibility for developing myositis as well as the prognosis. Whether there is an association between myositis and malignancies has been a subject of controversy for many years and recent epidemiological data have brought some clarification on this issue.

Adult↗

PubMed1996

Safe biotechnology. 7. Classification of microorganisms on the basis of hazard. Working Party "Safety in Biotechnology" of the European Federation Biotechnology.

The current systems for classifying human pathogens on the basis of hazard are well developed and their basic criteria are in general agreement one with another. Of more importance, the safety practices based on these classifications have generally been successful. They have enabled extensive research activities, medical practice and industrial production to be conducted on an ever-increasing scale, involving dangerous microorganisms (e.g. in vaccine production and treatment of infected patients) with a very low incidence of adverse effects on the workers involved and the general public. Although the EU has adopted a harmonised list of agents in groups 1-4 there is as yet no complete agreement among member states and individual microbiologists. The purpose of this paper is to present a historical survey and to discuss the current processes for identifying and classifying the hazards posed by the use of microorganisms in research and technology. This is essential in the design of appropriate methods of counteracting potential risks.

Bacteria↗

PubMed1995

[Classification of mood disorders in adults].

The two main classifications of mood disorders currently used are the American system, DSM, the fourth edition of which came out in 1994, and the International Classification of Diseases, the tenth edition of which was published in 1993. These classifications are based on the following broad principles: simple description with no hypothetical aetio-pathogenic discussion, distinction between the various clinical forms in accordance with variety and intensity of symptoms, co-existence of other more or less serious somatic disorders, individual identification of bipolar forms, etc. The key changes made in the classification of mood disorders between the revised version of DSMIII published in 1987 and DSM-IV published in 1994 suggest that a greater degree of concordance in diagnosis between different practitioners may be expected in future. In addition, certain changes such as the therapeutic decision-trees will most likely have an impact on practice. In this way, further details are added to the clinical criteria of duration or description of the clinical features seen, thereby allowing a clearer distinction to be made between normality and the onset of the pathology in question. Regarding bipolar disorders, the general organisation of the classification and the terminology used have been extensively revised, with the distinction between types I and II becoming official. Furthermore, differentiation between certain aspects of depression emphasises the frequency of certain clinical particularities, either in the onset or during the course of these disorders. This is true of melancholic, catatonic and atypical features specifiers (i.e. with mood reactivity and interpersonal rejection sensitivity), post-partum onset specifier, seasonal pattern specifier and rapid-cycling specifier. Finally, a certain number of specifications are proposed allowing the postulation of notions of complete or partial cure between episodes in case of recurrence.

Adult↗

PubMedDate not supplied

Infections caused by nondiphtheria corynebacteria.

After decades of confusion about their microbiologic classification and clinical significance, the nondiphtheria corynebacteria have emerged as important pathogens. Although isolation of these organisms may represent contamination with skin flora, several species, including Corynebacterium ulcerans, Corynebacterium pseudotuberculosis (Corynebacterium ovis), Corynebacterium haemolyticum, Corynebacterium pseudodiptheriticum, Corynebacterium equi, Corynebacterium bovis, Corynebacterium xerosis, and corynebacteria of group JK, clearly cause disease in humans. Most of these organisms infect animals, which are the source of human infection with some species. Some nondiptheria species of Corynebacterium produce recognizable clinical syndromes such as granulomatous lymphadenitis, pneumonitis, pharyngitis, cutaneous infections, and, most commonly, endocarditis. Certain species infect healthy hosts, while others predominantly attack immunocompromised individuals. Several species produce toxins, including a diphtheria-like toxin, a dermonecrotic toxin, and a soluble hemolysin. A microbiologic scheme of identification of the genus Corynebacterium and its major defined species is presented.

Animals↗

PubMed1999

Adult posttraumatic osteomyelitis of the tibia.

Posttraumatic tibial osteomyelitis results from trauma or nosocomial infection from the treatment of trauma that allows organisms to enter bone, proliferate in traumatized tissue, and cause subsequent bone infection. The resulting infection is usually polymicrobial. The patient may be classified using the May and the Cierny-Mader classification systems. The diagnosis is based on the isolation of the pathogen(s) from the bone, or blood cultures. Appropriate therapy of posttraumatic tibial osteomyelitis includes adequate drainage, thorough debridement, obliteration of dead space, stabilization when necessary, wound protection, and specific antimicrobial therapy.

Adult↗