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At least 649 records · Page 36Linked to original sources
PubMed1980

Variation in virulence for mice and rhesus monkeys among St. Louis encephalitis virus strains of different origin.

The virulence characteristics of 67 strains of St. Louis encephalitis (SLE) virus isolated from various sources in North, Middle, and South America were compared in mice and rhesus monkeys. Each virus strain was titrated in mice exactly 21 days old and virulence was expressed as the ratio of intracerebral (ic)/intraperitoneal (ip) LD50. Virus strains fell into three groups: 1) high virulence (ic/ip LD50 ratio approximately 1.0); 2) intermediate virulence (variable mortality over a wide dose range); and 3) low virulence (ic/ip LD50 less than or equal to 0.00002). Virus strains isolated during Culex pipiens and Cx. nigripalpus--borne epidemics in the eastern United States were highly virulent for mice, whereas a high proportion of the endemic virus strains isolated from Cx. tarsalis in the western United States were attenuated. Virus strains isolated from birds (the usual host for SLE virus) were highly virulent, in contrast to strains from rodents and carnivores, which were attenuated. Isolates from humans exhibited variable virulence characteristics. In experimentally-infected mice, virulence correlated with high viremia, replication in extraneural tissues, and earlier neuroinvasion. Mouse virulence correlated with clinical and histopathologic markers of pathogenicity for ic inoculated rhesus monkeys. Monkeys immunized with nonpathogenic strains by subcutaneous inoculation were partially protected against ic challenge with a virulent virus strain. The virulence classification of SLE virus strains is discussed in terms of epidemiologic correlations. This classification provides a framework for future studies on the antigenic, genetic, and biochemical bases for SLE virus strain variation.

Animals↗
PubMed1983

[Demonstration of bacteria in the ejaculate of subfertile men, with special reference to Chlamydiae].

Bacterial cultures were obtained from ejaculates of 87 infertile males with pathologic spermiogram (according to the classification of Elliason), and the presence of chlamydia was also examined. In no case chlamydia could be proved. In only 8% bacteria could be found in a pathogenic number (greater than 10(4)). The importance of asymptomatic bacteriospermia in infertility is discussed.

Bacteria↗
PubMed1994

The current role of Aspergillus and Penicillium in human and animal health.

Aspergillus and Penicillium are ubiquitous fungi, usually found as saprophytes. Only a few species are considered to be important in human or animal disease. However, many otherwise benign species are supreme opportunists and have been found increasingly as invaders of the immuno-compromised. This paper first describes with a broad brush modern approaches to the classification of these genera, the reasons behind some name changes and the effective forces now acting to stabilize names. Recent taxonomic schemes are described. The taxonomy of pathogenic Aspergillus and Penicillium species is outlined, the subgenera where pathogens occur identified, and the question of why particular species are pathogens addressed. The significance of Aspergillus and Penicillium in mammalian disease is heightened by their production of potent mycotoxins. The importance of Aspergillus flavus and aflatoxins as a cause of human death in parts of Africa and Asia and the impact of ochratoxins, produced by Penicillium verrucosum, on human and animal health in Europe will be emphasized. Possible mycotoxin ingestion from spores poses a further health threat.

Aflatoxins↗
PubMedDate not supplied

[Classification of prokaryotic species: the problem, demands, and methods of solving].

In accordance with the current approaches to the description of species of procaryotic organisms, they should be based on the comprehensive study of morphological, cultural, physiological, biochemical, serological, structure, genetic, molecular-biological, ecological and pathogenic peculiarities of the strains which are described as new species with finding unique and rather stable signs in them for to differ one group of strains from the other one, another set of unique and stable signs being determined for the latter. Thus, a species is a collection of original strains with high level of mutual similarity of the properties, if compare them with another group of relative strains. The strains which have changed key characteristics cannot be identified as the components of the already described species as well as a species cannot be described as based on the investigation of only one strain. Phenotypical signs of the strains composing a species would be identical, and the homology of their genome DNA would not be less than 70%, difference of melting temperatures of these molecules would not exceed 5 degrees C, and identity of sequences of their 16S rRNA is about 96%. The paper deals in detail with all the above propositions with analysis of their state in the world science with classification of procaryotes and specifying methodical and other requirements to the description of these species.

Phylogeny↗
PubMed1996

Use of repetitive intergenic DNA sequences to classify pathogenic and disease-suppressive Streptomyces strains.

PCR DNA fingerprinting using repetitive intergenic DNA sequences (rep-PCR) was investigated as a means of differentiating between closely related strains of Streptomyces which were, in some cases, indistinguishable by other classification methods. Our results demonstrated that the majority of strains had unique rep-PCR DNA fingerprints and established that the technique could be a very useful tool in rapidly determining strain identity.

Base Sequence↗
PubMed2026

Characterization and classification of a novel bacteriophage, vB_RsoP_HXg1W, infecting Ralstonia pseudosolanacearum: a new member of the genus Serkorvirus in the family Autotranscriptaviridae.

Bacterial wilt caused by Ralstonia solanacearum species complex (RSSC) is a significant threat to agriculture due to the pathogen's broad host range and persistence in soil. Bacteriophages (phages) are being explored as biocontrol agents, and such strategies are gaining interest. In this study, we isolated and characterized vB_RsoP_HXg1W, a novel phage propagated on R. pseudosolanacearum GMI1000. The phage has a linear double-stranded DNA genome of 40,184 bp with a GC content of 62.3%, and displays an icosahedral head with a short tail. A total of 51 open reading frames (ORFs) were identified, and no tRNA genes were detected. Comparative genomic and phylogenetic analyses revealed that vB_RsoP_HXg1W is closely related to Ralstonia phage p2137, p2106, and RpY2, and clusters within the genus Serkorvirus in the family Autotranscriptaviridae. VIRIDIC analysis revealed a maximum intergenomic similarity of 84.7% to the closest included relative, supporting vB_RsoP_HXg1W as a putative novel species-level member of Serkorvirus. These findings contribute to the understanding of RSSC-infecting phages and provide a foundation for further exploration of phage evolution, host range, and biocontrol relevant traits.

Ralstonia↗
PubMed2000

HIV and diarrhea in the era of HAART: 1998 New York State hospitalizations.

BACKGROUND: This study reflects an attempt to identify the causes of diarrheal illness in hospitalized HIV patients in light of therapeutic advancements in HIV management. METHODS: The study identifies the various etiologies associated with diarrhea among HIV patients hospitalized in New York State in 1998. Data for this study were extracted from the New York State Department of Health Statewide Planning and Research Cooperative System. Pathogens recognized to cause diarrhea in persons with HIV and general codes identifying diarrhea were examined by using the principal and all secondary diagnoses based on the International Classification of Diseases 9th Revision Clinical Modification codes. RESULTS: Based on the Statewide Planning and Research Cooperative System data set, more than 15,000 patients with HIV were hospitalized in 1998. Among the HIV patients hospitalized, 2.8% were admitted with a diarrheal diagnosis. The following diagnoses occurred the most frequently among HIV patients hospitalized with a diarrheal illness: Clostridium difficile (51.3%), other protozoal diseases (18.1%), and other organisms, not elsewhere specified (11.7%). CONCLUSIONS: In the era of highly active antiretroviral therapy, diarrhea is still an occurring symptom in HIV patients. Despite the relatively small percentage of hospitalizations attributed to diarrhea, clinicians must remember that even "mild" to "moderate" diarrhea can have a debilitating impact among persons with the symptom.

AIDS-Related Opportunistic Infections↗
PubMed2005

Anti-DNA antibodies: a diagnostic and prognostic tool for systemic lupus erythematosus?

The clinical impact of anti-DNA antibodies lies on their diagnostic power for systemic lupus erythematosus (SLE), being a formal classification criterion. In spite of such a disease association, low-avidity anti-DNA antibodies might also be part of the natural autoantibody repertoire. Their switch to pathogenic high-avidity autoantibodies is the result of the autoimmune process leading to SLE.Anti-DNA antibodies were shown to play a role in SLE pathogenesis and particularly in kidney damage. Accordingly, antibody titres might fluctuate in relation to disease activity, but their prognostic value for flares is still debated.Several methods for anti-DNA detection were described and there is evidence that the assays identify different antibodies with different prognostic value. The results of a multicenter study on four different routine tests for anti-dsDNA antibody detection showed that: (i) Farr assay displays the best diagnostic specificity/sensitivity for SLE, followed by Crithidia luciliae method (CLIFT), (ii) the new generation of solid phase assay (EliA) shows an increased sensibility versus the classical enzyme linked immune assay (ELISA) but a decreased specificity. Antibody titre detected by EliA and Farr assay correlated with disease activity. These findings would suggest that more than one assay should be useful for SLE diagnosis and monitoring.

Antibodies, Antinuclear↗
PubMed2005

Classification of bacterial species from proteomic data using combinatorial approaches incorporating artificial neural networks, cluster analysis and principal components analysis.

MOTIVATION: Robust computer algorithms are required to interpret the vast amounts of proteomic data currently being produced and to generate generalized models which are applicable to 'real world' scenarios. One such scenario is the classification of bacterial species. These vary immensely, some remaining remarkably stable whereas others are extremely labile showing rapid mutation and change. Such variation makes clinical diagnosis difficult and pathogens may be easily misidentified. RESULTS: We applied artificial neural networks (Neuroshell 2) in parallel with cluster analysis and principal components analysis to surface enhanced laser desorption/ionization (SELDI)-TOF mass spectrometry data with the aim of accurately identifying the bacterium Neisseria meningitidis from species within this genus and other closely related taxa. A subset of ions were identified that allowed for the consistent identification of species, classifying >97% of a separate validation subset of samples into their respective groups. AVAILABILITY: Neuroshell 2 is commercially available from Ward Systems.

Algorithms↗
PubMed2002

Modern aspects of immunopathogenesis of autoimmune myocarditis.

Myocarditis (MC) is an inflammation of the cardiac muscle. Viral infections appear to be the most frequent cause for induction of MC. According to the I. Roitt's classification, autoimmune (AI) MC is an organ-specific form of AI pathology. Thus, autoreactive antibodies (auto-Abs) against myocardial antigens and autoreactive T cells are major pathogenic mechanisms, and they are a common cause of cardiac muscle disorder progression. The autoantigens from myocardial tissue (like cardiomyosin and etc.) and/or the phenomena of virus mimicry stimulate auto-Ab production and their cross-reactivity with myocardial antigens. Some auto-Abs in patients with AI diseases demonstrate DNA-hydrolytic or proteolytic abilities against autoantigen. We found both DNA-abzymes and protabzymes in some MC patients. They showed catalytic activity not only against non-specific polypeptide, but also specific activity against cardiomyosine. Proteolytic activities of protabzymes differ depending on the clinical form and activity of MC. This suggests a role of protabzymes in the pathogenesis of AI-MC. According to some authors, auto-Abs (including auto-Abs with catalytic ability) in patients with AI diseases can be additional regulatory factors of apoptosis.

Antibodies, Catalytic↗
PubMed2004

Idiopathic interstitial pneumonias: progress in classification, diagnosis, pathogenesis and management.

The idiopathic interstitial pneumonias are a heterogeneous group of poorly understood diseases with often devastating consequences for those afflicted. Subclassification of the idiopathic interstitial pneumonia based on clinical-radiological-pathological criteria has highlighted important pathogenic, therapeutic and prognostic implications. The most critical distinction is the presence of usual interstitial pneumonia, the histopathological pattern seen in idiopathic pulmonary fibrosis. Idiopathic pulmonary fibrosis has a worse response to therapy and prognosis. New insight into the pathophysiology of usual interstitial pneumonia suggests a distinctly fibroproliferative process, and antifibrotic therapies show promise. While the clinical and radiographic diagnosis of idiopathic interstitial pneumonias can be made confidently in some cases, many patients require surgical lung biopsy to determine their underlying histopathology. A structured, clinical-radiological-pathological approach to the diagnosis of the idiopathic interstitial pneumonias, with particular attention to the identification of idiopathic pulmonary fibrosis, insures proper therapy, enhances prognostication, and allows for further investigation of therapies aimed at distinct pathophysiology.

Basement Membrane↗
PubMed1991

[Presence of various Acinetobacter species in urinary tract infections].

Species classification of 39 strains of Acinetobacter isolated from urinary tract infections (UTI) was performed by API 20NE tests. On the whole 24 biotypes were differentiated which formed 4 species and one biotype had no defined species classification. Acinetobacter baumani was most numerously represented. Seventy seven percent of strains were isolated from urine samples from women. About 90% of Acinetobacter strains were isolated as single pathogens. Sensitivity of these strains to 23 antibiotics and chemotherapeutics using ATB-UR and disc diffusion technique was evaluated. Of all cephalosporins tested ceftazidime was the most active. All strains tested were sensitive to imepenem. The high percentage of strains was sensitive to quinolones of IIIrd generation. The high percentage of strains was resistant to nitrofurantoin.

Acinetobacter↗
PubMed1994

[Histopathological findings of 59 cases of cheilitis granulomatosa].

By histopathological observations of 59 cases of CG, they are divided into 6 types according to pathological characteristics. Their differences are compared and discussed. The reason and significance of this classification from morphological point of view are discussed as well. It is suggested that the G is possibly resulted from different reactions of the body to the same pathogen or to the different pathogens.

Humans↗
PubMed2003

Pathogenic enterococci: new developments in the 21st century.

Enterococci, traditionally viewed as Gram-positive commensal bacteria inhabiting the alimentary canals of humans and animals, are now acknowledged to be organisms capable of causing life-threatening infections in humans, especially in the nosocomial environment. The existence of enterococci in such a dual role is facilitated, at least in part, by its intrinsic and acquired resistance to virtually all antibiotics currently in use. Beginning with the initial identification of a 'streptococci of fecal origin' in the late 19th century, enterococci have been studied for over a century now. A number of comprehensive reviews during this time have addressed various aspects of enterococci, including classification, biology, virulence, antibiotic resistance and so on. This review specifically addresses the important advances in the field of enterococcal research that have occurred since the beginning of the 21st century. Most notable among these developments have been the insights into enterococcal genomes and pathogenicity.

Adhesins, Bacterial↗
PubMedDate not supplied

Diagnosis, classification and treatment of partial-thickness rotator cuff tears.

Partial-thickness rotator cuff tears are a challenge for shoulder surgeons. There is still no standard treatment protocol. The recent introduction of new arthroscopic techniques and a better grasp of pathogenic mechanisms along with a greater functional demand from patients, have led to the need for a thorough analysis of the problem. This paper analyses the literature in order to simplify the approach to treating partial-thickness rotator cuff tears.

Arthroscopy↗
PubMed2006

Detection and characterization of Listeria monocytogenes in Sao Jorge (Portugal) cheese production.

Listeria monocytogenes is a foodborne pathogen that can cause serious invasive disease in humans. Because human listeriosis cases have previously been linked to consumption of contaminated cheese, control of this pathogen throughout the cheese production chain is of particular concern. To understand the potential for L. monocytogenes transmission via São Jorge cheese, a Portuguese artisanal cheese variety that bears a Protected Denomination of Origin classification, 357 raw milk, curd, natural whey starter, and cheese samples representative of the production chain of this cheese were collected over one year and tested for the presence of L. monocytogenes and selected physicochemical parameters. Although neither L. monocytogenes nor other Listeria spp. were detected in whey, curd, or cheese samples, 2 of the 105 raw milk samples analyzed were positive for L. monocytogenes. These 2 raw milk isolates represented a ribotype that has previously been linked to multiple human listeriosis outbreaks and cases elsewhere, indicating the potential of these isolates to cause human listeriosis. On average, physicochemical parameters of São Jorge cheese ripened for 4 mo presented values that likely minimize the risk of L. monocytogenes outgrowth during ripening and storage (mean pH = 5.48; mean moisture = 37.79%; mean NaCl concentration = 4.73%). However, some cheese samples evaluated in this study were characterized by physicochemical parameters that may allow growth and survival of L. monocytogenes. Even though our results indicate that raw milk used for São Jorge cheese manufacture as well as finished products is rarely contaminated with L. monocytogenes, continued efforts to control the presence of this pathogen in the São Jorge cheese production chain are urged and are critical to ensure the safety of this product.

Animals↗
PubMed2005

Historical aspects of idiopathic generalized epilepsies.

Early in these proceedings, the origin of the three terms in the title, "idiopathic generalized epilepsy," is discussed with respect to their significance over time, and typical misunderstandings. In the mid-20th century, a rather chaotic use of a multitude of often loosely defined terms had developed, which increasingly became an obstacle to a meaningful international discussion. The International League against Epilepsy (ILAE) took the initiative to develop an internationally accepted terminology with a classification system consisting of a classification of seizures (1981) and a classification of syndromes (1989). The Idiopathic Generalized Epilepsies are one of its four major groups emerging from a double dichotomy of generalized versus localization-related and idiopathic versus symptomatic. The inclusion of biologic aspects such as syndrome-specific ages of onset ("age-related syndromes") or syndrome-specific relations of seizure occurrence to the sleep-wake cycle ("Epilepsy with Grand Mal on Awaking") meant that the syndrome classification merged the more biological views of the German school with the more neurophysiological ones of the French. Apart from establishing a common international language concerning epilepsy, the International Classification of Epilepsies and Epileptic Syndromes became an important stimulator of research, especially concerning the idiopathic epilepsies. In particular, genetic and functional imaging investigations aim at a better understanding of these conditions. It is now understood that most idiopathic syndromes have a--sometimes complex--genetic background, but we are also becoming aware of the inappropriateness of the time-honored term "generalized" and part of our dichotomies. Both localization-related and "generalized" idiopathic epilepsies seem to share a principle of ictogenesis based on functional anatomic pathogenic networks, and we seem to move toward understanding them as functional system disorders of the brain.

Electroencephalography↗
PubMed2006

4. Autoimmunity, vasculitis, and autoantibodies.

Autoimmune diseases are distinct clinical syndromes characterized by various alterations in normal immune responsiveness, such that there is a loss of tolerance to particular host constituents. In most cases, despite years of intense investigation, the etiopathogenic antigens initiating these systemic inflammatory conditions remain undefined. However, a great deal has been learned about the changes in components of the immune response relevant to the propagation and sustenance of these often chronic disorders. In addition, various hormonal, environmental, physiologic, and other influences that affect their expression have been identified. The expression and ultimate clinical outcome of autoimmune diseases usually relate to inflammation-related damage to the target organ with subsequent dysfunction. Certain immune conditions, such as autoimmune thyroid disease, largely affect a single organ, whereas others, such as systemic lupus erythematosus, heterogeneously affect sundry organ systems. Autoantibodies directed against normal host antigens are a common feature of many autoimmune diseases. In some cases they are pathogenic, whereas in others they serve as markers for organ involvement or outcomes. Clinical descriptions of autoimmune diseases date back many decades in some cases. Recent efforts at formulating classification criteria have allowed clearer distinctions and more accurate stratification. Greater understanding of the immunopathogenesis of autoimmune conditions has led to the development and introduction into the clinic of novel immunomodulatory therapies and treatment paradigms that have substantially improved the outcomes for patients affected by these serious conditions.

Animals↗