Search PubMed⌕ Search

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.

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

At least 343 records · Page 19Linked to original sources
PubMed1998

[New classification and diagnostic criteria for diabetes mellitus].

The new Classification and Diagnostic Criteria for Diabetes Mellitus (DM), prepared by a group of experts from the American Diabetes Association is presented and analyzed. On an etiopathogenic basis, it designates Insulin Dependent and Non Insulin Dependent as Type 1 and Type 2 respectively. It specifies DM having specific known causes. It maintains Gestational Diabetes and Glucose Intolerance and adds the Impaired Fasting Glucose Condition. It recommends fasting plasma glucose for search and diagnosis, and lowers the level to > or = 126 mg/dl instead of > or = 140 mg/dl, due to its association with chronical complications of DM. It maintains the diagnostic criteria of random and post charge glycemia > or 200 mg/dl. It does not alter the glucose intolerance figure (140-200 mg/dl in OGTT) and introduces fasting abnormality > or = 110 and < 126 mg/dl. It encourages the search with fasting glucose every 3 years in individuals aged over 45, and at more frequent intervals in younger individuals with high risk factors. Analysis of the report allows to conclude that, although the classification does not introduce any significant change in daily clinical use, its pathogenic orientation makes future innovations possible. The preferential use of fasting glucose > or = 126 mg/dl for diagnosis of DM has theoretical basis and practical advantages. Identification of individuals with impaired fasting glucose allows to detect, in a simple manner, a high risk group in which to start preventive measures. However, there is a percentage of cases which are not diagnosed by fasting glycemia, but are diagnosed by OGTT, therefore the latter should not be discarded.

Blood Glucose↗
PubMed2004

In vitro investigation of voriconazole susceptibility for keratitis and endophthalmitis fungal pathogens.

PURPOSE: To update the spectrum of ocular fungal isolates and investigate the in vitro efficacy of voriconazole and other antifungals. DESIGN: Experimental study. METHODS: Microbiology database was scanned and fungal isolates associated with keratitis (419) and endophthalmitis (122) were analyzed for classification and isolate frequency. The Sensititre YeastOne microdilution antifungal susceptibility test was used to evaluate susceptibility (MICs) of 34 common fungal pathogens against amphotericin B, fluconazole, ketoconazole, 5-flucytosine, itraconazole, and voriconazole. Ten of the test isolates were sent to a reference laboratory to validate the Sensititre results. RESULTS: Fusarium species remains the most frequent corneal fungal pathogen (60.1%). Colletotrichum species (4.1%) has emerged as the fifth most common mold in keratitis. Top yeast isolates from cornea included Candida albicans (52.3%) and Candida parapsilosis (37.3%). Half of the intraocular pathogens were Candida species. Paecilomyces (2.9%) and Philophora (1.9) were unusual pathogens. In vitro susceptibility profiles were voriconazole (100%), ketoconazole (82.4%), amphotericin (76.5%), itraconazole (67%), fluconazole (60%), and 5-FC (60%). Voriconazole MIC(90) were lowest for Candida species (0.016 microg/ml) and highest for Fusarium species (2 microg/ml). Reference laboratory MICs correlated 100% for yeast isolates (0.016 microg/ml) but were fourfold higher for Fusarium species (8 microg/ml). MIC(90) for Aspergillus species was 0.5 microg/ml. CONCLUSIONS: Candida, Fusarium, and Aspergillus species remain frequent fungal pathogens. Voriconazole may have a role in the therapeutic management of Candida and Aspergillus ocular infections. Clinical efficacy must determine the role for other fungal pathogens. Human use and animal models will determine its use in the clinical setting.

Antifungal Agents↗
PubMed1996

[Molecular biology of enteroviruses].

Molecular biological methods offer new approaches to the study of RNA viruses. On the example of enteroviruses we tried to give an account, of recent progress in the knowledge and understanding of these important human pathogens. Firstly concerning their structural and genomic organisation; secondly as regards understanding of their pathology and pathogenicity; thirdly the impact of such methods on rapid, sensitive and specific diagnosis, treatment, on epidemiology and finally on evolution and classification of the large picornavirus family where the enterovirus genus belongs. We believe that molecular biology will elucidate still unknown features of enteroviruses, which are not yet correctly evaluated human pathogens.

Enterovirus↗
PubMed2026

Molecular clusters and precision medicine in pheochromocytomas and paragangliomas.

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors derived from chromaffin cells of the adrenal medulla and extra-adrenal paraganglia. Over the past two decades, the genomic characterization of PPGLs has profoundly transformed their diagnosis, classification, risk stratification, and therapeutic management. Up to 40% of PPGLs harbor germline pathogenic variants, the highest proportion among human neoplasms, and somatic driver events are identified in a substantial fraction of the remaining cases. Integrative multi-omic studies have established three main molecular clusters: a pseudohypoxic cluster driven by Krebs-cycle alterations (SDHx, FH, MDH2, DLST) and HIF-2&#x3b1; pathway alterations (VHL, EPAS1, EGLN1/2); a kinase-signaling cluster driven by activation of RAS/MAPK and PI3K/AKT pathways (RET, NF1, HRAS, TMEM127, MAX); and a Wnt-signaling cluster characterized primarily by MAML3 fusions. This review summarizes progress in PPGL genomics, highlighting geographic and sex-related particularities. Using EPAS1/HIF-2&#x3b1; and RET as paradigmatic examples, we illustrate how diverse germline, somatic, mosaic, and fusion events converge on common core signaling hubs that can be therapeutically exploited with FDA-approved selective inhibitors for relevant targets (e.g. belzutifan for HIF-2&#x3b1;; selpercatinib and pralsetinib for RET). We further review the genomic determinants of metastatic risk (SDHB, ATRX, TERT, and MAML3 fusions), the immune microenvironment of metastatic disease, and emerging radionuclide theranostics, liquid biopsy biomarkers, and integrative multi-omic approaches that are reshaping precision medicine for PPGLs.

Humans↗
PubMed1993

[Chromobacterium violaceum, opportunist pathogenic bacteria in tropical and subtropical regions].

Chromobacterium violaceum is isolated from soil and waters in tropical and subtropical areas. This Gram negative bacillus is considered as a saprophyte, but occasionally it can act as an opportunistic pathogen for animals and man, and cause fatal septicaemia from skin lesion with many liver and lung abscesses. Classification, nomenclature, media used to isolation, characters useful to identification (morphology, cultural and biochemical traits, violacein pigmentation), differentiation from related violet-pigmented species and from Vibrionaceae (when C. violaceum cultures are not pigmented), antibiotics resistance and susceptibility, experimental and natural pathogenicity are emphasized.

Animals↗
PubMed1995

A definition of advanced types of atherosclerotic lesions and a histological classification of atherosclerosis. A report from the Committee on Vascular Lesions of the Council on Arteriosclerosis, American Heart Association.

This report is the continuation of two earlier reports that defined human arterial intima and precursors of advanced atherosclerotic lesions in humans. This report describes the characteristic components and pathogenic mechanisms of the various advanced atherosclerotic lesions. These, with the earlier definitions of precursor lesions, led to the histological classification of human atherosclerotic lesions found in the second part of this report. The Committee on Vascular Lesions also attempted to correlate the appearance of lesions noted in clinical imaging studies with histological lesion types and corresponding clinical syndromes. In the histological classification, lesions are designated by Roman numerals, which indicate the usual sequence of lesion progression. The initial (type 1) lesion contains enough atherogenic lipoprotein to elicit an increase in macrophages and formation of scattered macrophage foam cells. As in subsequent lesion types, the changes are more marked in locations of arteries with adaptive intimal thickening. (Adaptive thickenings, which are present at constant locations in everyone from birth, do not obstruct the lumen and represent adaptations to local mechanical forces). Type II lesions consist primarily of layers of macrophage foam cells and lipid-laden smooth muscle cells and include lesions grossly designated as fatty streaks. Type III is the intermediate stage between type II and type IV (atheroma, a lesion that is potentially symptom-producing). In addition to the lipid-laden cells of type II, type III lesions contain scattered collections of extracellular lipid droplets and particles that disrupt the coherence of some intimal smooth muscle cells. This extracellular lipid is the immediate precursor of the larger, confluent, and more disruptive core of extracellular lipid that characterizes type IV lesions. Beginning around the fourth decade of life, lesions that usually have a lipid core may also contain thick layers of fibrous connective tissue (type V lesion) and/or fissure, hematoma, and thrombus (type VI lesion). Some type V lesions are largely calcified (type Vb), and some consist mainly of fibrous connective tissue and little or no accumulated lipid or calcium (type Vc).

Aneurysm↗
PubMed1995

A definition of advanced types of atherosclerotic lesions and a histological classification of atherosclerosis. A report from the Committee on Vascular Lesions of the Council on Arteriosclerosis, American Heart Association.

This report is the continuation of two earlier reports that defined human arterial intima and precursors of advanced atherosclerotic lesions in humans. This report describes the characteristic components and pathogenic mechanisms of the various advanced atherosclerotic lesions. These, with the earlier definitions of precursor lesions, led to the histological classification of human atherosclerotic lesions found in the second part of this report. The Committee on Vascular Lesions also attempted to correlate the appearance of lesions noted in clinical imaging studies with histological lesion types and corresponding clinical syndromes. In the histological classification, lesions are designated by Roman numerals, which indicate the usual sequence of lesions progression. The initial (type I) lesion contains enough atherogenic lipoprotein to elicit an increase in macrophages and formation of scattered macrophage foam cells. As in subsequent lesion types, the changes are more marked in locations of arteries with adaptive intimal thickening. (Adaptive thickenings, which are present at constant locations in everyone from birth, do not obstruct the lumen and represent adaptations to local mechanical forces). Type II lesions consist primarily of layers of macrophage foam cells and lipid-laden smooth muscle cells and include lesions grossly designated as fatty streaks. Type III is the intermediate stage between type II and type IV (atheroma, a lesion that is potentially symptom-producing). In addition to the lipid-laden cells of type II, type III lesions contain scattered collections of extracellular lipid droplets and particles that disrupt the coherence of some intimal smooth muscle cells. This extracellular lipid is the immediate precursor of the larger, confluent, and more disruptive core of extracellular lipid that characterizes type IV lesions. Beginning around the fourth decade of life, lesions that usually have a lipid core may also contain thick layers of fibrous connective tissue (type V lesion) and/or fissure, hematoma, and thrombus (type VI lesion). Some type V lesions are largely calcified (type Vb), and some consist mainly of fibrous connective tissue and little or no accumulated lipid or calcium (type Vc).

Aneurysm↗
PubMed1982

Application of flow cytometry to studies of pathogenic free-living amoebae.

Species of small, free-living amoebae of the genera Naegleria and Acanthamoeba can cause fatal amoebic meningoencephalitis. Previous investigations have shown that pathogenic amoebae are associated with thermally altered water. Flow cytometric techniques for identifying species of pathogenic and nonpathogenic amoebae from such water have been developed, using immunofluorescence and fluorescein-bound concanavalin A. Flow cytometry is accomplished with a cytofluorograph, in which cells are dispersed in a suspended carrier liquid and passed in front of a focused argon ion laser beam. Cells are then distinguished by the degree of scattered light (size) or fluorescence. Flow cytometry techniques have proven efficient for environmental samples, as indicated by the identification of pathogenic Naegleria fowleri and nonpathogenic Naegleri gruberi and Acanthamoeba castellanii isolated from the Savannah River Plant in South Carolina. Cytofluorographic analysis of environmental samples has several advantages over the current methods of isolation and classification of free-living amoebae. With this system, it is possible to rapidly identify species and quantitate mixtures of pathogenic amoebae in environmental samples. Cytofluorographic analysis of amoebic isolates reduces the time presently required to screen environmental sites for pathogenic amoebae. The cytofluorograph permits detection and species identification of nonthermophilic Naegleria spp. and Acanthamoeba spp. that could not easily be isolated for species identification by conventional methods. Other advantages of flow cytometry over fluorescent microscopy include a high degree of statistical precision due to the large numbers measured, high immunofluorescent titers, and elimination of subjectivity and fluorescence fading.

Agglutination Tests↗
PubMed1998

Pathology of human immunodeficiency virus infection: infectious conditions.

Infection with the human immunodeficiency virus (HIV) and the subsequent derangement of host immunity place affected patients at risk for secondary infections. Some of the secondary pathogens occur with such frequency or are so rare in the non-immunosuppressed population that they have become part of the Centers for Disease Control and Prevention (CDC) classification for HIV/acquired immune deficiency syndrome (AIDS). Other infectious agents not yet included in the CDC definition are being reported in the HIV-infected population with increased frequency. General observations of the degree of immunosuppression associated with specific secondary infections have been useful in developing classification systems for HIV disease such as that of the CDC. However, the specific alterations in host immunity that promote infection with specific secondary pathogens are generally unknown. Geographic differences in the types and frequency of secondary infections also have been reported. Variation in strains of HIV, effect of malnutrition, lack of appropriate medical treatment, prevalence of virulent infectious diseases, and epidemiologic differences are possible contributing factors. Some infections that seemed likely to be closely associated with HIV infection have not occurred more frequently in HIV-infected patients. This review summarizes the histopathology of infectious conditions in the current CDC classification and highlights some conditions seen in HIV-infected individuals that are not currently HIV/AIDS-defining infections, yet may be seen by practicing pathologists.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Problems of food hygiene with carriers of microorganisms and permanent excretors].

To appraise the significance of chronic excretors and carriers for the development of "food poisoning", the analysis must also include the food. First of all, the question arises as to whether foods only have a vector function or whether an increase in the bacterial count is an important prerequisite for the elicitation of human disease. When pure intoxication pathogens are not involved, this question arises in connection with the minimum infectious dose. A classification of the most important causative organisms of bacterial foodborne infections and intoxications is presented in the light of these considerations. If foods only have a vector function, hygiene measures are automatically concentrated on excretors in order to prevent the bacteria from passing into foods. When this is not the case (as in the vast majority of human foodborne infections and intoxications of bacterial origin), two strategies can be successfully applied. First of all, precautions must be taken to rule out bacterial contamination. On the other hand, an increase in the bacterial count, i.e. proliferation of the pathogens in the food must be prevented by appropriate measures. The interacting factors are described. The example of salmonellae is cited to illustrate the routes of contamination from excretors (humans and animals) to foods ready for consumption and possible hygiene measures.

Animals↗
PubMed2024

A framework for automated scalable designation of viral pathogen lineages from genomic data.

Pathogen lineage nomenclature systems are a key component of effective communication and collaboration for researchers and public health workers. Since February 2021, the Pango dynamic lineage nomenclature for SARS-CoV-2 has been sustained by crowdsourced lineage proposals as new isolates were sequenced. This approach is vulnerable to time-critical delays as well as regional and personal bias. Here we developed a simple heuristic approach for dividing phylogenetic trees into lineages, including the prioritization of key mutations or genes. Our implementation is efficient on extremely large phylogenetic trees consisting of millions of sequences and produces similar results to existing manually curated lineage designations when applied to SARS-CoV-2 and other viruses including chikungunya virus, Venezuelan equine encephalitis virus complex and Zika virus. This method offers a simple, automated and consistent approach to pathogen nomenclature that can assist researchers in developing and maintaining phylogeny-based classifications in the face of ever-increasing genomic datasets.

Animals↗
PubMed2002

WHO and ADA criteria for the diagnosis of diabetes mellitus in relation to body mass index. Insulin sensitivity and secretion in resulting subcategories of glucose tolerance.

OBJECTIVE: To determine the influence of body mass index (BMI) on agreement between the American Diabetes Association (ADA) and the new World Health Organization diagnostic criteria for the diagnosis of diabetes mellitus and to investigate the metabolic profile of the resulting subcategories. DESIGN: Cross-sectional study SUBJECTS: A total of 3018 subjects with no previous history of diabetes and fasting glucose <7.8 mmol/l, with a wide range of BMIs. MEASUREMENTS: (1) Prevalence of impaired glucose regulation (IGR) and diabetes (DM) according to ADA and WHO diagnostic criteria; (2) basal and post-load insulin sensitivity and secretion, calculated on the basis of data derived from an oral glucose tolerance test (OGTT). RESULTS: The diagnosis according to the two classifications was concordant in 2490 subjects, discordant in 528 (452 were identified as impaired glucose tolerance (IGT) and 76 as DM only by means of OGTT). The disagreement increased with increasing BMI, being as high as 25.3% in subjects with BMI > or = 35 kg/m(2). Subjects with isolated fasting hyperglycaemia were mainly characterised by reduced insulin sensitivity and secretion in the basal state, but normal first-phase insulin secretion and moderately reduced insulin sensitivity after glucose challenge. Subjects with isolated 2 h hyperglycaemia were mainly characterised by normal basal insulin secretion and by a marked insulin resistance associated with a blunted first-phase insulin secretion after the glucose load. CONCLUSIONS: The disagreement between ADA and WHO classifications is particularly relevant in obesity, making OGTT mandatory in these subjects. Different pathogenic mechanisms are involved in isolated fasting or post-load hyperglycaemia, possibly related to a different site of insulin resistance (hepatic vs peripheral), and/or to a different disregulation of insulin secretion (basal vs post-load). A correct identification of the underlying mechanism(s) is the rationale for future studies to detect the effectiveness of different pharmacological or behavioural approaches.

Adolescent↗
PubMed1998

Pathophysiology and treatment of idiopathic hypercalciuria.

Nearly 50 years after its initial description by Dr. F. Albright, the term idiopathic hypercalciuria (IH) is still in use. The exact mechanism of hypercalciuria is still unknown despite extensive pathophysiologic investigations; recent advances represent the focus of this review. A precise definition of true IH is proposed, taking into account the various nutritional conditions influencing calcium excretion. The potential pathogenic mechanisms are discussed, and the limits of the classical Pak's pathophysiological classification are recalled. The evidence supporting the role of an increased intestinal calcium absorption, a defect in renal tubular calcium reabsorption, or an increased bone loss as a primary mechanism in IH are successively examined. Since overall available human data indicates that all three mechanisms may be found in IH, the hypothesis that a broader disorder encompassing all these various abnormalities may be involved in IH is discussed. Three global hypotheses to account for IH physiopathology are examined: a diffuse defect in fatty acid content of cell membranes, an increased expression of the vitamin D receptor of the 25(OH) vitamin D 1 alpha-hydroxylase, or of the calcium sensor receptor and a monocyte disease. Finally, the available clinical data justifying the therapeutic approaches are reviewed, and guidelines for dietary recommendations regarding calcium and also animal protein, sodium chloride, alcohol, carbohydrate, phosphate, and potassium intakes are proposed, and drug therapy indications are discussed.

Bone Diseases, Metabolic↗
PubMed2001

Occurrence of two superoxide dismutases in Aeromonas hydrophila: molecular cloning and differential expression of the sodA and sodB genes.

Aeromonas spp., considered as emerging opportunistic pathogens, belong to the family Vibrionaceae. Among the criteria currently used for their classification is the presence of a single FeSOD (iron-containing superoxide dismutase), which distinguishes them from Enterobacteriacea. In this paper the cloning of the sodA and sodB genes encoding two different SODs in Aeromonas hydrophila ATCC 7966 is reported. The sodB gene encoded an FeSOD (196 amino acids, 21.5 kDa), was constitutively expressed and showed 75% homology with the E. coli FeSOD. The sodA gene encoded a protein of 206 amino acids (22.5 kDa) with MnSOD (manganese-containing SOD) activity and showed 55% homology with the Escherichia coli MnSOD. The MnSOD of A. hydrophila was detected only during the stationary phase of growth under high aeration or when induced by lack of iron. Nevertheless, paraquat had no detectable effect on its production. The amino-terminal part of the Mn-containing protein contained a putative signal sequence which could permit a periplasmic localization.

Aeromonas↗
PubMed1997

Review: hepatitis delta.

The causative agent of hepatitis delta virus (HDV) is the most unusual of all causative agents for all hepatitis viruses. Current knowledge of the molecular biology of HDV strengthens its proposed classification within the satellites, a family of subviral agents, some of which are pathogens of higher plants. Hepatitis delta virus is the only virus in the satellite family known to infect animal species, with hepatitis D having affected more than 10 million people worldwide who are also infected with its helper virus, HBV. Recently, the world map for hepatitis D appears somewhat modified, with decreasing HDV prevalence in certain areas and some new foci of HDV endemicity. Despite changing HDV prevalence, hepatitis. D, particularly the chronic form, is still an important health problem worldwide in terms of morbidity and mortality (mainly due to chronic liver disease, including hepatocellular carcinoma). Molecular studies have greatly advanced our understanding of the life cycle of HDV and of the function of its proteins. The new molecular information is of clinical relevance, with implications for the pathogenesis of liver damage, the diagnosis of HDV infection, for the natural course of the disease and, potentially, for therapy. Sensitive assays for HDV-RNA by polymerase chain reaction and sequencing techniques have clarified the patterns of HDV transmission and have confirmed the existence of unusual clinical forms of the virus and their relationship to replicative levels and genotypes of HDV. Prevention and treatment of hepatitis D are still in their infancy. However, liver transplantation for delta cirrhosis has proven far more successful than in any other viral form of cirrhosis, with few reinfections of the grafted liver, and has given important information on HDV biology and the pathogenesis of liver damage.

Animals↗
PubMed1994

High frequency of HLA-DQB1*0301 allele in patients with pure ocular cicatricial pemphigoid.

Two factors, is classification and its immunogenetics, may have contributed to an incomplete understanding of the pathogenic mechanism in the disease group commonly termed 'cicatricial pemphigoid'. We have previously demonstrated that pure ocular cicatricial pemphigoid (OCP) is a unique clinical and immunopathological entity. In an effort to better define the immunogenetic characteristics for patients with pure OCP, we performed HLA typing for the class II MHC gene HLA-DQB1*0301 allele, by amplifying genomic DNA extracted from patients with polymerase chain reaction, followed by hybridization with a sequence-specific oligonucleotide probe on dot-blotted and Southern-blotted amplified DNA samples. Ninety percent (9/10) of patients with pure OCP had the DQB1*0301 allele, in contrast to 52% (17/33) of normal individuals who had the DQB1*0301 allele. The high frequency of the HLA-DQB1*0301 allele in patients with pure OCP may point to a distinct immunogenetic pattern and possibly a distinct pathomechanism for the disease.

Alleles↗
PubMed1983

Treatment of atypical mycobacterial disease.

The most common disease patterns produced by atypical mycobacteria are pulmonary disease, cervical lymphadenitis, and infection of soft tissue, bones, and joints. The treatment of disease due to atypical mycobacteria can be confusing unless one clearly differentiates the organisms according to clinical characteristics and response to various chemotherapeutic agents. For this reason, we have attempted to simplify the task by proposing a new classification system. The organisms that might be isolated from human material are divided into the following three classes: nonpathogens; those that are easy to treat with standard mycobacterial therapy; and finally, those that are difficult to treat with standard mycobacterial therapy and require other approaches. This new system of classification should help the clinician in dealing with these organisms. Because even the pathogens may sometimes appear as a contaminant in human material, including sputum, one must document that these organisms are associated with disease prior to instituting therapy.

Drug Resistance, Microbial↗
PubMed1992

[Blastocystis hominis: in search of a disease, a misunderstood organism].

Blastocystis hominis is a micro-organism which remains somewhat mysterious. Having defined its present position in the classification of Protozoa, the authors describe its ultrastructure and morphology. Its epidemiology and pathogenicity are discussed in the light of experimental studies and human clinical data, especially in AIDS patients. Metronidazole seems to be the most active drug against this organism, but extreme caution must be exerted when the possible pathogenic property of B. hominis is discussed.

Animals↗