SEARCH · Search PubMed
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.
Dermatological lesions of a patient are studied and investigated. It is suggested that they belong to a syndrome rather than to an entity. The following etiological classification of the mossy syndrome is proposed: due to bacteria, fungi and viruses, and secondary to other dermatopathies. Bibliography is reviewed.
Statistical parameters of nucleotide sequences of mature human RNAs and those of human viruses were compared. The redundancy values of the appropriate genes were compared. The redundancy of virus genes was shown to be, on the average, less than that of human genes. The distribution of human genes according to redundancy values is bimodal, and that of human virus genes is trimodal. This fact suggests possibility of a novel gene classification according to statistical characteristics of nucleotide sequences.
The main forms of "noncoronarogenous" diseases of the heart muscle and the problems of their nomenclature are discussed, an attempt is made in particular to determine the borderline between the concepts of "myocardial dystrophy" and "cardiomyopathy". The article also deals with the role of infections in the origin of inflammatory processes in the heart muscle (myocarditis) and its dystrophy. A conclusion is drawn on the expediency, from the standpoint of nomenclature, to designate the pathological condition of the myocardium in the course of an infectious disease only by the term "myocarditis". The relation between "primary cardiomyopathies" and Fiedler's idiopathic myocarditis is discussed. The possible role of virus infection in the origin of the indicated forms of myocardial diseases is considered. The classification of noncoronarogenous myocardial lesions published in Kardiologia (1978, No. 5) is discussed. The author of the present article thinks that it may be appraised quite favourably on the whole, and also makes some remarks.
OBJECTIVE: To determine if the signs and symptoms of genital herpes in pregnancy accurately identify primary genital herpes infections using serologic testing for final classification. METHODS: Twenty-three women with clinical signs and symptoms suggestive of primary genital herpes infections in the second and third trimesters of pregnancy were subsequently cultured and tested serologically (for herpes simplex virus type 1 and herpes simplex virus type 2 antibodies) and classified as having true primary (no herpes simplex virus type 1 or type 2 antibodies), nonprimary (heterologous herpes simplex virus antibodies present), or recurrent (homologous antibodies present) infections. RESULTS: Only one of 23 women with clinical illnesses consistent with primary genital herpes virus simplex infections had serologically-verified primary infection. This primary infection was caused by herpes simplex virus type 1. Three women had nonprimary type 2 infections, and 19 women had recurrent infections. Among culture-proven recurrent infections, 12 were caused by herpes simplex virus type 2 and three by herpes simplex virus type 1. Only one infant was born preterm, and no clinically significant perinatal morbidity was observed. CONCLUSION: Correct classification of gestational genital herpes infections can be accomplished only when clinical evaluation is correlated with viral isolation and serologic testing using a type-specific assay. Severe first episodes of genital herpes infections among women in the second and third trimesters of pregnancy are not usually primary infections and are not commonly associated with perinatal morbidity.
The genomic sequence of human T-cell leukemia virus type 1 (HTLV-1) is highly conserved, although minor sequence variations enable classification of the isolates into several subgroups. We previously reported, however, that the Tax-coding sequence of HTLV-1 genome is highly variable in a random fashion within individuals with HAM/TSP and asymptomatic carriers. Here, we describe frequent base substitutions in the LTR sequence similarly to those in Tax-coding sequence. These observations indicate that frequent mutations are not unique to the sequence encoding the most effective antigen for cytotoxic T lymphocytes, but also seen in the LTR, a non-coding sequence. Thus, frequent mutations seem to occur during the viral replication process rather than the selection of rare mutants by immune surveillance.
Despite a late beginning, the construction of the arenavirus taxon and its placement in the scheme of the International Committee on Taxonomy of Viruses has now been completed. The bringing together of the member viruses has already provided valuable indications of promising laboratory and field study approaches; in the future this classification will contribute further to our understanding of the natural history and disease processes of the human pathogens of the group.
Antisera prepared against 16 strains of hantaviruses isolated from patients with hemorrhagic fever with renal syndrome (HFRS) or from rodents captured in HFRS-endemic and nonendemic regions were titrated against Hantaan virus strain 76-118, Puumala virus strain Sotkamo, and Prospect Hill virus strain Prospect Hill-I by using the indirect immunofluorescent antibody and plaque reduction neutralization tests. Isolates fell into one of four distinct groups or serotypes. Serotype 1 included Apodemus-derived strains, serotype 2 included Rattus-derived strains, serotype 3 included Clethrionomys-derived strains, and serotype 4 included Microtus-derived strains. Serotypic classification of hantavirus infections was possible for humans and rodents in widely varied geographical areas, but in a few instances, sera from patients with HFRS did not conform to any of the four serotypes, suggesting the existence of as yet unidentified serotypes. A definitive serological classification of hantaviruses must await analysis of additional virus isolates.
A PCR protocol was established that not only allows the detection of, but also the differentiation of species of the genus Orthopoxvirus. This assay was accomplished by the selection of oligonucleotides located within the gene that encodes the A-type inclusion protein of cowpox virus. The primer pair flanked a region exhibiting distinct and specific DNA deletions in the corresponding sequences of vaccinia, mousepox, monkeypox and camelpox virus. For this reason, PCR resulted in DNA fragments of different sizes. The presented PCR protocol, combined with BglII restriction digests, allowed the unequivocal assignment of 42 orthopoxvirus (OPV) strains and isolates to the correct OPV species. The resulting classification corresponded exactly with known biological data for the OPV strains investigated. Furthermore, 13 out of 22 cowpox virus isolates could be subtyped by the presence or absence of a small BglII fragment. DNA sequencing showed that the lack of this BglII fragment was caused by a deletion of 72 nucleotides.
UNLABELLED: The evolutionary origins and taxonomic framework of giant viruses related to the family Mamonoviridae and its relative group, including clandestinovirus, remain unclassified due to gaps in genome size and host range between these two groups. This study aimed to address this gap by integrating our newly isolated virus with publicly available metagenome-assembled genomes (MAGs) to construct a more robust phylogenetic framework. Here, we report the isolation and characterization of a new giant virus, furtivovirus, using the unicellular amoeba Vermamoeba vermiformis as a host. Furtivovirus has a genome of approximately 560 kbp and shares key features with its closest relative, clandestinovirus. Ultrastructural analysis revealed a unique host-nucleus-dependent replication strategy characterized by the breakdown of the nuclear membrane and the packaging of nascent virions directly within the nucleoplasm, distinguishing it from canonical cytoplasmic virion factories. Comprehensive phylogenetic and comparative genomic analyses of shared orthologous groups and nucleocytovirus marker proteins revealed that furtivovirus, clandestinovirus, ushikuvirus, and usurpativirus form a distinct monophyletic clade, for which we propose a new family, "Manesviridae." Further analysis using amino acid-based similarity metrics of Nucleocytoviricota viral genomes, including established MAGs, demonstrated that this new family is robustly placed as a sister group to the family Mamonoviridae. This study elucidated the evolutionary relationships between viruses with large and small genomes that possess similar virion sizes within this lineage. Based on this cumulative evidence, we propose the establishment of a new order to unify these two families, thereby expanding their diversity and clarifying the evolutionary history of this branch within Nucleocytoviricota. IMPORTANCE: Giant viruses challenge our traditional understanding of viral evolution, raising the question of how a single related group can diverge to infect different hosts while evolving into vastly different genome sizes and replication strategies. The family Mamonoviridae and its relatives epitomize this evolutionary divergence: one group possesses massive genomes, whereas the other has genomes that are less than half their size. The discovery of furtivovirus and its unique nucleoplasm-dependent replication cycle provides a critical biological context for this genomic disparity. Through deep comparative genomic analysis, we demonstrated that these seemingly disparate lineages share a cohesive evolutionary origin that is distinct from other established orders. This finding highlights the complexity of genome evolution, demonstrating that giant viruses can expand their overall genome size to adapt to uncertain environments while reducing their core essential genes, thereby providing new insights into the evolutionary pressures that shape the diversity of the virosphere.
BACKGROUND: The outbreaks of acute gastroenteritis caused by a virus are currently one of the health problems having the greatest impact on those living in senior citizen facilities. The objective of this study is that of investigating the causes of the start and contagion of an outbreak of acute gastroenteritis caused by a Norwalk-Like virus. METHOD: At a senior citizen living facility with 141 residents and 71 employees exposed, the relations between the disease in question and different independent variables: personal traits, features of location, date of onset of symptoms, clinical pattern of the disease and causal factors (food and drinking water intake). A descriptive study, a contingency table and a hypothesis ?2 test, design of cases and controls with the calculation of the unprocessed and subsequently adjusted Odds Ratio (IC 95%) were carried out using logic regression. RESULTS: No significant differences were found in the personal trait and features of location variables. The attack rate among the residents was 30.1%, being 21.12% among the employees. In the adjusted Odds Ratio calculation, solely the whipped cream mousse showed causal relationship values (adjusted Odds Ratio = 4.66; IC-95% 1.15-18.91; p = 0.031). Ten patient stool samples were sent for analysis, no disease-causing bacteria having been detected, Norwalk-Like virus however having been isolated in three samples. CONCLUSIONS: The whipped cream mousse having been found to possibly have been responsible for the outbreak is a first involving Norwalk virus, but this result is subject to limitations, such as the possible bias of classification due to failing to recall having eaten foods. Even so, this is an element to be taken into account in the control of acute viral gastroenteritis.
Explore the source record for details and available documents.
If the relationships between baculoviruses and their insect hosts are subject to coevolution, this should lead to long-term evolutionary effects such as the specialization of these pathogens for their hosts. To test this hypothesis, a phylogeny of the Baculoviridae, including 39 viruses from hosts of the orders Lepidoptera, Diptera, and Hymenoptera, was reconstructed based on sequences from the genes lef-8 and ac22. The tree showed a clear division of the baculoviruses according to the order of their hosts. This division highlighted the need to reconsider the classification of the baculoviruses to include one or possibly two new genera. Furthermore, the specialization of distinct virus lineages to particular insect orders suggests ancient coevolutionary interactions between baculoviruses and their hosts.
The data presented in this report show that the enveloped Mycoplasmatales virus MVL2 is capable of interferon induction in sheep peripheral blood lymphocytes. The phenomenon was dose dependent, requiring approximately 10(8) plaque-forming units of virus per 2 X 10(6) lymphocytes. The interferon was stable to pH 2.0 treatment, was produced in moderately high levels (greater than 1,000 units), and met many of the criteria for classification as a type I interferon. Heat-inactivated MLV2 lost its ability to induce interferon, whereas ultraviolet-inactivated virus retained its capacity to induce levels comparable to untreated virus. Whereas the MVL2 used in these studies was contaminated with several host cell proteins as determined by sodium dodecyl sulfate-containing polyacrylamide gel electrophoresis, the contaminants probably did not play a role in the induction because isolated cell membranes or soluble cell contents from Achoplasma laidlawii are inactive as inducers. Also presented in this report is a preliminary description of the structural polypeptides of MVL2.
Multiple sclerosis (MS) is a chronic disease of the central nervous system characterized by chronic inflammation and demyelination. Studies suggested that the viral, especially Epstein-Barr virus infection, and bacterial infections, especially Borrelia burgdorferi infection, play a role in etiology of MS. MS prevalence parallels the distribution of the Lyme disease pathogen B. burgdorferi. Criteria used for diagnosis of MS can also be fulfilled in other conditions such as Lyme disease, a multisystem disorder resulting from infection by the tick-borne spirochete, B. burgdorferi. In the late period of Lyme disease demyelinating involvement of central nervous system can develop and MS can be erroneously diagnosed. A Lyme borreliosis can mimick central nervous system lymphoma. Also, B. burgdorferi has been implicated not only in etiology of MS, but also in etiology of lymphoma. Studies suggested that there is an increased risk of non-Hodgkin lymphoma in patients, who had a history of autoimmune diseases such as MS and that both non-Hodgkin's lymphomas and Hodgkin's disease were associated with Epstein-Barr virus infection. A small group of lymphomas called primary effusion lymphomas (PEL) is a recently individualized form of non-Hodgkin's lymphoma (WHO classification) that exhibit exclusive or dominant involvement of serous cavities, without a detectable solid tumor mass. These lymphomas have also been linked to Epstein-Barr virus and human herpes virus type 8 infections but virus negative cases have been described. Therefore, we propose that MS and neuroborreliosis are linked to central nervous system primary effusion lymphomas. As a first step in confirming or refuting our hypotheses, we suggest a thorough study of CSF in the patients suspected for the diagnosis of MS and Lyme borreliosis.
VIVA is a software library that obtains low-resolution models of icosahedral viruses from projections observed at the electron microscope. VIVA works in a fully automatic way without any initial model. This feature eliminates the possibility of bias that could originate from the alignment of the projections to an external preliminary model. VIVA determines the viewing direction of the virus images by computation of sets of single particle reconstruction (SPR) followed by a variance analysis and classification of the 3D models. All structures are reduced in size to speed up computation. This limits the resolution of a VIVA reconstruction. The models obtained can be subsequently refined at best with use of standard libraries. Up today, VIVA has successfully solved the structure of all viruses tested, some of which being considered refractory particles. The VIVA library is written in 'C' language and is devised to run on widespread Linux computers.
Human adenoviruses (HAdVs) are the major causes of a variety of acute illnesses. Virus isolation and neutralization tests are usually done to identify the causative virus, but these tests are labor-intensive and time-consuming, and standardized antisera are in limited supply. This study investigated a rapid and reliable method of virus identification based on PCR and phylogenetic analysis. The phylogenetic tree constructed by neighbor joining on the basis of the newly determined partial hexon sequences from 33 prototypes of HAdV-D and -E, along with 11 available prototypes of HAdV-A to -C and -F from GenBank, allowed HAdVs to be grouped into six distinct clusters. These clusters correspond closely to the six newly designated species, HAdV-A to -F. The partial hexon sequences of 57 isolates from patients with acute conjunctivitis obtained over 20 years plus those of 44 prototype strains were analyzed. Each isolate formed a monophyletic cluster along with its respective prototype strain, allowing serotype identification. Partial-hexon-based classification appears to be an effective tool for studying the molecular epidemiology of HAdVs.
Seven hundred and twelve patients from cancer screening, pregnancy care, outpatient clinics for patients at risk for cervical dysplasia and human immunodeficiency virus (HIV) infection were tested simultaneously for cytological aberrations and human papillomavirus (HPV). Classification of these cases, and of all cytology records throughout 1991 and 1992 was performed according to the "Münchner Nomenklatur" and the Bethesda classification. HPV-directed polymerase chain reaction analysis was carried out with general primers, patients at risk for cervical dysplasia were tested by subsequent hybridization with HPV 16 and 18 probes. Patients from cancer screening and pregnancy care showed similar HPV prevalences ranging between 19.4%-24.6%. In contrast, patients from dysplasia and HIV units were infected in 56.2%-62.3% and 75.0%-76.9% respectively in centre of disease control stage III-IV, HPV detection rates in patients from dysplasia and HIV units increased gradually from 40.1%-52.9% in non-suspicious smears to 80.8%-100% in atypical smears. High risk HPV 16 and 18 infections were detected in 64% of smears with cytological evidence of HPV infection (koilocytosis) to 84.2% in severe dysplasia. Following the Bethesda guidelines, 2.9%-14.7% of all smears initially reported as Pap 2 K (suggestive of HPV infection) would be qualified as risk lesions (low grade squamous intraepithelial lesions), although they tested HPV negative in more than a third of cases. Thus, when using the Bethesda system, HPV analysis is needed to prevent overclassification and overtreatment. The "Münchner Nomenklatur" avoids this dilemma by not mixing morphological statements on infection, atypia and cancer risk.
Cryoglobulins are immunoglobulins that precipitate at low temperature and dissolve when warmed. According to Brouet, their classification relies upon the immunochemical study: type I comprises monoclonal immunoglobulins (IGG), when types II and III include both monoclonal and polyclonal components. During C hepatitis, the presence of a cryoglobulin, essentially made of mixed G-IGG and M-IGG, is a common feature with a prevalence of 40 to 80%. The authors report a case of a 63-year patient who presented with a vascular purpura and a peripheral polyneuropathy in a context of C hepatitis infection. The cryoglobulin found was composed of a monoclonal kappa A-IgG associated with a biclonal kappa and lambda M-IgG. No decrease of normal IgGs was found. This type of cryoglobulin does not belong to Brouet's classification, and argues for a new and more pertinent classification to be proposed.