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At least 1,009 records · Page 56Linked to original sources
PubMed2006

Isolation and characterization of a Sagiyama virus from domestic pigs.

In 2002, a strain of Sagiyama virus (SAGV) designated ML/Taiwan/02 was isolated from farmed pigs in Taiwan. The nsP1 and E1 gene sequences of the ML/Taiwan/02 strain shared 98.6 and 96.7% homology, respectively, with corresponding genes of a Japanese strain of SAGV. Nucleotide and amino acid sequence comparison revealed this strain of SAGV to be most closely related to Getah virus, as opposed to its current classification as a subtype of Ross River virus. To investigate the seroprevalence of SAGV infection in Taiwan, a total of 586 pig sera collected from 11 of 17 Taiwanese districts were tested for serum neutralizing antibodies (SNA) against SAGV. Results indicated that 51% of the samples had SNA titer > or = 4, and 40% had SNA titer > or = 48, indicative of repeated exposure to SAGV in the field. To study the pathogenicity of the ML/Taiwan/02 strain, this strain was experimentally inoculated into 4-week-old specific-pathogen-free pigs that were seronegative for SAGV. Viremia was detected during postinoculation days (PID) 2-4, when the SNA titer was < or = 16. By PID 7, viremia was no longer detectable, coinciding with the increase of SNA titer to > or = 48. Clinical illnesses or remarkable lesions were not observed. To the authors' knowledge, this is the first reported isolation of a strain of SAGV from pigs in the field. The virus is experimentally nonpathogenic to pigs but is moderately widespread, most likely via repeated exposure to virus-carrying mosquitoes.

Alphavirus Infections↗
PubMed1992

[Occurrence of bacteria of the Yersinia genus in surface water].

The aim of the study was determination of the frequency of occurrence of Yersinia genus bacteria in surface waters polluted to various degrees with bacteria of the coliform and of fecal coli. For detection of Yersinia rods the previously elaborated medium Endo MLCe and the membrane filter method were applied. Samples of 42 surface waters were examined, including 26 from rivers and 16 from lakes, ponds and clay-pits. On the basis of sanitary bacteriological analysis 16 surface waters were classified to class I purity, 10 to class II, the remaining ones to class III or beyond classification. Yersinia rods were detected in 15 water bodies that is 35.7% of the examined waters. A total of 27 Yersinia strains were identified with dominance of Y. intermedia (14 strains) and Y. enterocolitica (10 strains). Three strains represented by the species Yersinia frederiksenii. Most of the Y. enterocolitica strains belonged to biotype 1, the particular strains being represented by various serotypes. Hence their different origin may be concluded. The pathogenic serotypes 0:3 and 0:9 of Yersinia enterocolitica were not detected.

Water Microbiology↗
PubMed1998

[Classification and concept of mycobacterial infections].

Mycobacterial infections are consisted of three categories; tuberculosis, nontuberculous mycobacterioses, and leprosy. Tuberculosis is a systemic infectious disease involving respiratory, genitourinary and lymphatic systems caused by Mycobacterium tuberculosis complex (Mycobacterium tuberculosis, M. bovis, M. africanum, and M. microti). Extrapulmonary tuberculosis remains a significant clinical problem because symptoms and signs may be difficult to recognize and to relate to tuberculosis. Miliary tuberculosis is responsible for up to 10% of predominantly extrapulmonary cases. HIV-related miliary tuberculosis is rapidly progressive and almost always fatal without treatment. Nontuberculous mycobacteria (NTM) have been commonly implicated as opportunistic pathogens in patients with underlying disease or immunosuppression including AIDS. M. avium complex (M. avium and M. intracellulare) and M. kansashii are most common causes of nontuberculous mycobacterial diseases in humans. M. leprae is the causative agent of leprosy, an infection of the skin, mucous membranes, and peripheral nerves. This disease is rare in Japan, yet it remains a major problem in some part of the world.

Female↗
PubMed2005

[Biodiversity of Capillariinae].

The subfamily Capillariinae includes about 300 species of nematodes parasitizing all groups of vertebrates. Taxonomy and systematics of this parasites have been changed many times because of a difficulty in designation of particular species' features. That's why there are a lot of synonyms in this group. Nowadays most authors accept the systematics, of Capillariinae according to Moravec. Biology and ecology of species parasitizing breeding birds and mammals is well known, however data relative to capillaria of wild animals are fragmentary. Capillariinae parasitize in various part of alimentary system: mainly in intestine, stomach, duodenum, rarely in oesophagus, rectum or bursa of Fabricius and liver as well as respiratory and excretory systems. Pathogenicity depends on localization of nematodes and the age of the hosts, and on infection intensity. Species recorded in human beings are: Aonchotheca philippinensis, Eucoleus aerophilus and Calodium hepaticum. They are a cause of intestinal, lung and hepatic capillariosis.

Animals↗
PubMed2000

Evaluating patients with arthritis of recent onset: studies in pathogenesis and prognosis.

Inflammatory synovitis of recent onset poses a diagnostic and prognostic challenge to primary care physicians and rheumatologists. A lack of understanding of the underlying etiologic and pathogenic processes limits the ability to distinguish forms of arthritis that follow a benign, self-limiting course from forms that proceed to an aggressive, erosive disease requiring intensive immunosuppressive therapy. It is estimated that between 30% and 40% of patients presenting with early synovitis have disease that remains unclassified. Using data from a cohort of patients with early synovitis and reviewing current literature, we discuss investigational approaches toward a new classification of patients with early synovitis. Although a lack of understanding of this heterogeneous clinical syndrome has led clinicians to take a largely empirical approach to treatment thus far, the evolving awareness of disease predisposition at a genetic level and the expanding ability to specifically manipulate biological pathways may ultimately change the approach to this clinical problem. JAMA. 2000;284:2368-2373.

Adult↗
PubMedDate not supplied

Lipid analysis for the identification of mycobacteria: an appraisal.

A review is presented of the use of lipid analysis by thin-layer chromatography for the identification and classification of mycobacteria. Specific lipid patterns are known for 15 species (in some cases a species may exhibit more than one pattern), and these patterns normally correlate well with serotypes. In six species the lipid pattern is not very distinctive but can still be useful. No specific lipid patterns have been detected in 15 species, three of which can be classed as tubercle bacilli, and only two of the remainder are pathogenic for humans.

Chromatography, Thin Layer↗
PubMed1983

DNA cleavage patterns as indicators of genotypic heterogeneity among strains of Acholeplasma and Mycoplasma species.

Electrophoretic patterns of digestion products of Acholeplasma and Mycoplasma DNA by restriction endonucleases were compared. The patterns of Acholeplasma axanthum strains isolated from a variety of hosts and habitats differed markedly from each other, indicating considerable genotypic heterogeneity among strains included in this species. Heterogeneity was less marked among the Acholeplasma oculi strains tested, and was minimal among strains of the avian pathogen Mycoplasma gallisepticum. Strains of Mycoplasma genitalium isolated from the urethra of patients with non-gonococcal urethritis and from the urethra of an experimentally infected chimpanzee yielded identical cleavage patterns, indicating a high degree of genetic homogeneity of these strains. The data support the notion that mycoplasma species of strict host and tissue specificity exhibit marked genetic homogeneity. The advantages and deficiencies of the use of DNA cleavage patterns for classification purposes are discussed.

Acholeplasma↗
PubMed1977

[The problem of the cardiomyopathies].

The author criticizes the tendency to broaden continuously the notion of "cardiomyopathy" and the attempts to cover by this term almost all etiological and pathogenetic variants of myocardial lesions. Classification of these variants by two groups is proposed: 1) idiopathic cardiomyopathies, etiology of which are either not known, or not established yet; 2) symptomatic cardiomyopathies the causes of which are known. The first group comprises congestive and hypertrophic cardiomyopathies. Their essential clinico-anatomical features and considerations concerning pathogenesis are set forth. Every variant of the second group of cardiomyopathies (symptomatic) is analysed separately according to the character of the pathogenic agent. The need for comprehensive study of myocardial pathology in the so-called cardiomyopathies is emphasized.

Cardiomegaly↗
PubMed1993

[Diagnosis in urinary tract infections].

For a rational diagnostic work-up of urinary tract infections (UTI), a detailed history and a standardised examination of smear material, prostatic fluid and urine are essential. Examination of the urine is simple, with test strips, microscopic examination of the sediment and determination of the bacterial count by the dipstick procedure having proved their worth in practice. Isolation and identification of pathogens and the preparation of an antibiogram require special knowledge of microbiological techniques. Accurate evaluation of the urine and its constituents requires a knowledge of how the urine has been collected; we recommend spontaneously passed urine in men and young children, and catheter urine in women. Acute complicated and chronic recurrent UTIs require radiological studies and sonography. Occasionally, nuclear-medical investigations and angiography or CT may be necessary for detailed classification. In cases of obstruction of the lower UT or neurogenic problems with urinary bladder, urodynamic investigation and endoscopy must be performed. This stepwise diagnostic evaluation allows both optimal classification of the UTI and a saving in costs.

Bacterial Infections↗
PubMed1997

[Chronic paroxysmal hemicrania].

In order to provide an update of clinical, pathogenic, diagnostic and therapeutic aspects of chronic paroxysmal hemicrania (CPH), also known as Sjaastad syndrome, we review the relevant literature. The term CPH was proposed by Sjaastad in 1976. Although continuous and non continuous cases have been described, Sjaastad prefers to use the term "prechronic" for the non continuous form, given that the adjective "chronic" denotes an important defining feature of CPH. CPH, which has been included in International Headache Society classification system since 1988, is much less common than cluster headache. CPH can be defined as pain that mainly affects women, is unilateral, always on the same side, and generally oculo-fronto-temporal. It can appear at any hour of the day or night, can be triggered by various phenomena and is accompanied by dysautonomic phenomena, generally on the same side as the pain, such as red eyes, tearing, nasal congestion and sometimes rhinorrhea. This headache is distinguished by its response to indomethacin therapy. The pathogenesis of CPH is unknown, although it is believed to resemble cluster headache, at least in its final stages (involving the trigeminal vascular system). Differential diagnosis should include cluster headache, SUNCT syndrome, continuous hemicrania and cervical headache, as well as facial neuralgia.

Adult↗
PubMed2026

Deep learning-assisted, pathogenesis-informed lung histopathology scoring in preclinical mouse models of SARS-CoV-2 and influenza A infection.

INTRODUCTION: SARS-CoV-2 and influenza A virus (IAV) cause viral pneumonia, yet their lung lesions evolve with distinct spatial organization and resolution-phase architecture. In preclinical murine studies, H&E histopathology is a primary endpoint, but burden-focused semiquantitative scoring can miss pathogen- and phase-specific differences in lesion topology, compartmental involvement, inflammatory organization, and repair. We aimed to define virus- and phase-specific morphologic signatures and translate them into a practical, pathogenesis-informed scoring guide, supported by whole-slide convolutional neural network (CNN) analysis with class activation mapping (CAM). METHODS: Mice were infected under standardized conditions and evaluated during the early, peak-injury, and late phases of infection, corresponding to 2~3, 5~8, and 14 days post-infection (dpi), respectively. Lungs were assessed by H&E with semiquantitative scoring and by immunostaining to map viral antigen distribution and epithelial tropism. Whole-slide CNN models were trained for virus- and phase-specific classification, and CAM localized discriminative regions. RESULTS: Dose titration established reproducible lethal and sublethal infection conditions for both viruses. Viral antigen kinetics diverged, with SARS-CoV-2 peaking early and declining toward clearance by the resolution phase, whereas IAV peaked later and declined by the resolution phase, paralleling distinct injury-repair trajectories. CNN/CAM analysis distinguished virus- and phase-specific histologic patterns across the early, peak-injury, and resolution phases of infection and highlighted spatial signatures consistent with expert review. At the peak-injury phase, SARS-CoV-2 lungs showed broad alveolar/interstitial involvement, whereas IAV exhibited bronchocentric inflammatory organization. During the resolution phase, IAV showed prominent epithelial regeneration with remodeling-forward architecture, while SARS-CoV-2 more often retained localized residual inflammatory foci. Across both infections, tissue inflammatory composition shifted over time, with higher neutrophil representation during the peak-injury phase and a relative increase in lymphocytic representation during the resolution phase. Integrating lesion topology/distribution, edema, epithelial injury-regeneration, remodeling features, and lymphocyte predominance, we proposed a pathogen-resolved, phase-informed histopathology scoring guide with recommended evaluation windows for each model. CONCLUSION: Together, these findings define virus- and phase-specific morphologic programs that inform respiratory virus pathogenesis in mice and can be translated into practical scoring criteria for preclinical respiratory virus studies.

Animals↗
PubMed2003

Screening of Bifidobacterium strains isolated from human faeces for antagonistic activities against potentially bacterial pathogens.

As probiotic bacteria, strains belonging to the genus Bifidobacterium colonise the gastro-intestinal tract of humans and animals at the time of birth, and they are found in young as well as in adult individuals in great numbers. Moreover, they can interact with the development of enteric infections by the production of antimicrobial metabolites. In this work 281 strains of bifidobacteria were anaerobically isolated from human faecal samples, supplied by volunteers of different ages (youngs, adults, elders), and preliminarly described by microscopic observation. All strains were screened by the fructose 6-phosphate phosphoketolase (F6PPK) test in order to confirm their classification within the genus Bifidobacterium. Selected strains were used to evaluate their antagonistic activities against Escherichia coli, Salmonella thyphimurium, Staphylococcus lentus, Enterococcus faecalis, Acinetobacter calcoaceticus, Sphingomonas paucimobilis, Listeria monocytogenes, Yersinia enterocolitica, Bacillus cereus, Clostridium sporogenes. Experiments were performed in vitro by different methods based on the observation of growth inhibition in Petri dishes. The strains that showed the highest inhibiting activities were compared by SDS-PAGE for total cell proteins, using type strains of human origin as references. Representative isolates were metabolically characterised by the BIOLOG system; a specific database was created with strains obtained from our collection and a statistical evaluation for metabolic patterns was carried out.

Adolescent↗
PubMed1986

The clinical significance of gastrointestinal helminths--a review.

Gastrointestinal helminths (nematodes, trematodes and cestodes) constitute some of the most common and important infective agents of mankind and are responsible for much morbidity and some mortality. Whereas many symptoms and signs are confined to the intestine and less often the associated digestive organs, systemic manifestations are also numerous; this applies especially to indigenous populations of developing 'Third World' countries. Using a clinical classification these organisms can be broadly separated into those involving the small-intestine and those which have a colo-rectal distribution; of the former, a minority has been causally related to intestinal malabsorption. Clearly, however, not all gastrointestinal helminths are associated with disease and it is important to be able to separate these two groups; when present at high concentration and especially in infants and children some of the least pathogenic are not, however, entirely asymptomatic. Maintenance of a high 'index of suspicion' is necessary and this applied especially to 'western' populations in whom rapid and extensive travel to areas of the world with substandard sanitation and contaminated food and water supplies is now common; first evidence of infection in them may result from serious clinical complications. Recent advances have focussed on treatment, and especially the introduction of the benzimidazole compounds (especially albendazole) for nematode, and praziquantel for cestode, infections. Treatment of strongyloidiasis remains, however, unsatisfactory. Mass elimination of gastrointestinal helminths in developing 'Third World' countries remains a major challenge.

Adult↗
PubMed2004

Biological agents with potential for misuse: a historical perspective and defensive measures.

Biological and chemical agents capable of producing serious illness or mortality have been used in biowarfare from ancient times. Use of these agents has progressed from crude forms in early and middle ages, when snakes and infected cadavers were used as weapons in battles, to sophisticated preparations for use during and after the second World War. Cults and terrorist organizations have attempted the use of biological agents with an aim to immobilize populations or cause serious harm. The reasons for interest in these agents by individuals and organizations include relative ease of acquisition, potential for causing mass casualty or panic, modest financing requirement, availability of technology, and relative ease of delivery. The Centers for Disease Control and Prevention has classified Critical Biological Agents into three major categories. This classification was based on several criteria, which include severity of impact on human health, potential for delivery in a weapon, capacity to cause panic and special needs for development, and stockpiling of medication. Agents that could cause the greatest harm following deliberate use were placed in category A. Category B included agents capable of producing serious harm and significant mortality but of lower magnitude than category A agents. Category C included emerging pathogens that could be developed for mass dispersion in future and their potential as a major health threat. A brief description of the category A bioagents is included and the pathophysiology of two particularly prominent agents, namely anthrax and smallpox, is discussed in detail. The potential danger from biological agents and their ever increasing threat to human populations have created a need for developing technologies for their early detection, for developing treatment strategies, and for refinement of procedures to ensure survival of affected individuals so as to attain the ultimate goal of eliminating the threat from intentional use of these agents. International treaties limiting development and proliferation of weapons and continuing development of defense strategies and safe guards against agents of concern are important elements of plans for eliminating this threat.

Anthrax↗
PubMed2003

Time-series analysis of MRI intensity patterns in multiple sclerosis.

In progressive neurological disorders, such as multiple sclerosis (MS), magnetic resonance imaging (MRI) follow-up is used to monitor disease activity and progression and to understand the underlying pathogenic mechanisms. This article presents image postprocessing methods and validation for integrating multiple serial MRI scans into a spatiotemporal volume for direct quantitative evaluation of the temporal intensity profiles. This temporal intensity signal and its dynamics have thus far not been exploited in the study of MS pathogenesis and the search for MRI surrogates of disease activity and progression. The integration into a four-dimensional data set comprises stages of tissue classification, followed by spatial and intensity normalization and partial volume filtering. Spatial normalization corrects for variations in head positioning and distortion artifacts via fully automated intensity-based registration algorithms, both rigid and nonrigid. Intensity normalization includes separate stages of correcting intra- and interscan variations based on the prior tissue class segmentation. Different approaches to image registration, partial volume correction, and intensity normalization were validated and compared. Validation included a scan-rescan experiment as well as a natural-history study on MS patients, imaged in weekly to monthly intervals over a 1-year follow-up. Significant error reduction was observed by applying tissue-specific intensity normalization and partial volume filtering. Example temporal profiles within evolving multiple sclerosis lesions are presented. An overall residual signal variance of 1.4% +/- 0.5% was observed across multiple subjects and time points, indicating an overall sensitivity of 3% (for axial dual echo images with 3-mm slice thickness) for longitudinal study of signal dynamics from serial brain MRI.

Algorithms↗
PubMed2003

Fibromyalgia--from syndrome to disease. Overview of pathogenetic mechanisms.

According to the classification criteria proposed by the American College of Rheumatology, fibromyalgia is a long-standing multifocal pain condition combined with generalised allodynia/hyperalgesia. It is the generalised allodynia/hyperalgesia that distinguishes fibromyalgia from other conditions with chronic musculoskeletal pain. Central sensitisation of nociceptive neurons in the dorsal horn due to activation of N-methyl-D-aspartic acid receptors and disinhibition of pain due to deficient function of the descending inhibitory system are probable pathogenic factors for allodynia/hyperalgesia. Furthermore, chronic pain is a chronic emotional and physical stressor. Chronic stress and chronic sleep disturbance are not specific for fibromyalgia but could be the causes of symptoms like fatigue, cognitive difficulties and other stress-related symptoms. They may also cause neuroendocrinological and immunological aberrations.

Fibromyalgia↗
PubMed2005

Comparative analyses of fundamental differences in membrane transport capabilities in prokaryotes and eukaryotes.

Whole-genome transporter analyses have been conducted on 141 organisms whose complete genome sequences are available. For each organism, the complete set of membrane transport systems was identified with predicted functions, and classified into protein families based on the transporter classification system. Organisms with larger genome sizes generally possessed a relatively greater number of transport systems. In prokaryotes and unicellular eukaryotes, the significant factor in the increase in transporter content with genome size was a greater diversity of transporter types. In contrast, in multicellular eukaryotes, greater number of paralogs in specific transporter families was the more important factor in the increase in transporter content with genome size. Both eukaryotic and prokaryotic intracellular pathogens and endosymbionts exhibited markedly limited transport capabilities. Hierarchical clustering of phylogenetic profiles of transporter families, derived from the presence or absence of a certain transporter family, showed that clustering patterns of organisms were correlated to both their evolutionary history and their overall physiology and lifestyles.

Biological Transport↗
PubMed1993

Bacteriology and immunology of normal and diseased adenoids in children.

Adenoid physiology as reflected in the qualitative and quantitative bacteriology and immune cell distribution was correlated with clinical presentation in 69 children (16 to 130 months of age) undergoing adenoidectomy for obstructive adenoid hyperplasia (n = 38) or chronic adenoid infection (n = 31) and in 16 adenoid core biopsy specimens from 16 nondiseased controls. In the control adenoids, few potentially pathogenic bacteria were found as the dominant bacteria in the adenoid core (25%), and significantly greater concentrations of nonpathogens (commensals) were isolated (P < .01). Potential pathogens as the dominant bacteria were found twice as often in obstructive adenoid hyperplasia (62%) and in chronic adenoid infection (55%) (P < .05). Haemophilus influenzae was most common in the diseased adenoids, 53% in obstructive adenoid hyperplasia and 48% in chronic adenoid infection, compared with only 19% in the controls (P < .05). No significant differences in lymphocyte density, B and T cells, as well as T-helper subsets, were found between clinical classifications. However, T-suppressor cells, monocytes-macrophages, and natural killer cells were significantly increased in chronic adenoid infection only (P < .05). The findings in this study support roles for both alterations in bacterial homeostasis and an altered immune profile in the etiology of chronic adenoid disease in children.

Adenoids↗