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At least 739 records · Page 41Linked to original sources
PubMed1988

Neuromuscular diseases associated with human immunodeficiency virus infection.

The types of neuromuscular diseases associated with human immunodeficiency virus (HIV) infection are described. Our classification includes: (1) six subtypes of peripheral neuropathies--namely, acute Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, mononeuritis multiplex, an axonal, predominantly sensory, painful polyneuropathy, a sensory ataxic neuropathy due to ganglioneuronitis, and an inflammatory polyradiculoneuropathy presenting as cauda equina syndrome; (2) inflammatory myopathies (e.g., polymyositis); and (3) other less common neuromuscular manifestations, such as type II muscle fiber atrophy and nemaline myopathy. Although the exact incidence of clinical and subclinical neuromuscular diseases in HIV-positive and acquired immunodeficiency syndrome (AIDS) patients is unknown, estimates vary from 15 to almost 50% of such individuals. The type of neuropathy or myopathy related to the specific stage of HIV infection, the pathogenetic mechanisms involved, and effective therapies are discussed. A neuromuscular disease not only occurs in patients with AIDS and AIDS-related complex, but it can coincide with HIV seroconversion or it can be the only clinical indication of a chronic silent HIV infection. Chronic asymptomatic HIV infection should be considered in the differential diagnosis of certain acquired inflammatory polyneuropathies or myopathies. Precautions needed when doing electromyographic studies are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Classification of papillomaviruses.

One hundred eighteen papillomavirus (PV) types have been completely described, and a yet higher number of presumed new types have been detected by preliminary data such as subgenomic amplicons. The classification of this diverse group of viruses, which include important human pathogens, has been debated for three decades. This article describes the higher-order PV taxonomy following the general criteria established by the International Committee on the Taxonomy of Viruses (ICTV), reviews the literature of the lower order taxa, lists all known "PV types", and interprets their phylogenetic relationship. PVs are a taxonomic family of their own, Papillomaviridae, unrelated to the polyomaviruses. Higher-order phylogenetic assemblages of PV types, such as the "genital human PVs", are considered a genus, the latter group, for example, the genus "Alpha-Papillomavirus". Lower-order assemblages of PV types within each genus are treated as species because they are phylogenetically closely related, but while they have distinct genomic sequences, they have identical or very similar biological or pathological properties. The taxonomic status of PV types, subtypes, and variants remains unchanged and is based on the traditional criteria that the sequence of their L1 genes should be at least 10%, 2-10%, and maximally 2% dissimilar from one another.

Papillomaviridae↗
PubMed2003

Human rhinoviruses.

Human rhinoviruses are the most important causative agents of upper respiratory infections and are also implicated in more severe clinical entities. Although often present, very little is known about human rhinoviruses. Molecular methods have been used in the classification of this large group of viruses into two separate clades. In addition, one known serotype was found to be a member of enterovirus group D. Laboratory diagnosis of human rhinovirus infection is based on reverse transcription polymerase chain reaction methods or the more tedious virus culture but a rapid "bedside" method is unavailable. Anti-rhinoviral therapy has been under extensive study over the past few decades but symptomatic treatment of the common cold is still the only useful approach in clinical use. More data on circulating human rhinovirus strains would facilitate both detection and treatment of these common pathogens.

Acute Disease↗
PubMed1989

A new epidemiologic and laboratory classification system for paralytic poliomyelitis cases.

An epidemiologic classification of paralytic poliomyelitis cases (ECPPC) has been in use in the United States since 1976. In 1985, this classification system was reviewed because of recent changes in the epidemiology of paralytic poliomyelitis and improved laboratory capability to definitively characterize poliovirus strains. An alternative classification system was devised, the epidemiologic and laboratory classification of paralytic polio cases (ELCPPC), that incorporated virus isolation and strain characterization with epidemiologic information. Reported paralytic poliomyelitis cases for 1980-86 were classified by both the ECPPC and the ELCPPC classification systems. The new ELCPPC system classified 91 per cent of the reported cases as vaccine-associated, while the ECPPC system classified only 71 per cent of the reported cases as vaccine-associated. The proposed classification system provides more specific and useful information particularly concerning vaccine-associated paralytic poliomyelitis.

Epidemiologic Methods↗
PubMed1993

[Clinical significance of cholestatic viral hepatitis].

Modern serologic methods permit the classification of the particular course a virus hepatitis takes into individual types of pathogenesis. This is the case with hepatitis A in which only cholestatic courses have been proved for sure. Cholestatic courses are observed in 5-10% of all cases of acute hepatitis A, with variations from country to country. The duration of the disease is considerably longer than in non-cholestatic hepatitis A. It is between 80 and 130 or even more days! The diagnostic difficulty consists in the clear delimination to other diseases, particularly to intrahepatic cholestasis by drugs or to posthepatic stenosis. Sonography and ERCP are useful technological methods in this situation. Specific therapeutical measures are not available due to the lack of knowledge of the pathogenesis of this type of acute virus infection. The prognosis of cholestatic hepatitis A is good. Short-term glucocorticoid therapy is recommended by some authors in long-term cases, which are associated with pruritus, general weakness, loss of weight and distinct icterus. The course of the disease is obviously not changed by this therapy, but the sometimes agonizing symptomatology is relieved.

Cholestasis, Intrahepatic↗
PubMed2001

The growing threat of arbovirus transmission and outbreaks in Kenya: a review.

OBJECTIVE: To review the trend in arbovirus outbreaks and activity in Kenya in the last ten years. DATA SOURCE: Published reports of past outbreak investigations and more recent data available at the Arbovirology and Viral haemorrhagic fevers reference centre, Centre for Virus Research, Nairobi. STUDY SELECTION: Past and recent outbreaks and active transmission reports of arboviruses of medical importance in Kenya including Yellow fever (YF), Rift Valley Fever (RVF), Dengue and Crimean Congo haemorrhagic fever. SYNTHESIS: Each of the viruses was reviewed providing critical information on classification, incidence, outbreak, and activity in Kenya, mode of transmission, recognition of cases, management and control. CONCLUSION: There is increased frequency of outbreaks and detection of arbovirus activity in humans and vectors in the last ten years including re-emergence of YF virus as a public health concern in Kenya. The importance of recognition of cases and diagnosis (especially in malaria endemic areas) is critical to management and control. Effective countrywide surveillance backed by diagnostic centres is highly recommended.

Animals↗
PubMed2003

Assessing the feasibility of using neural precursor cells and peripheral blood mononuclear cells for detection of bioactive Sindbis virus.

Viruses form a significant class of bio-threat agents. Currently, the only method to determine the bioactivity of viruses in vitro is to measure viral and cellular responses after co-incubation of cells with virus. Our goal is to find biomarkers for classification of agents, establishment of bioactivity, and/or prediction of disease outcomes. To begin development of a cell-based biosensor for detection of bioactive Sindbis virus (SV), our model analyte, we surveyed the outcomes of SV interaction with primary rat neural precursor cells (NPC) and human peripheral blood mononuclear cells (PBMC). Confocal fluorescence analysis of NPC treated with recombinant SV carrying green-fluorescent-protein (SV-GFP) showed that most cells were GFP positive by day 1 post inoculation. 4',6-Diamidino-2-phenylindole dihydrochloride (DAPI) staining of the nucleus showed nuclear condensation and fragmentation, and the percentage of TUNEL positive cells were higher in virus-treated cells than in mock-treated control. Also, there were less BrdU positive cells in virus-treated cells compared to control. Thus, SV infects NPC, decreases cellular proliferation, and induces cell death via apoptosis. PBMC were treated with SV- or UV-inactivated SV. By day 5 post infection, there were fewer adherent cells in SV-treated PBMC compared to UV-inactivated SV treated PBMC. However, the percentage of viable cells remained the same, and virus growth curves showed only clearance of virus. Thus, SV induces detachment of a subpopulation of PBMC while not killing most of the cells. Together, these results indicate that NPC and PBMC respond to bioactive SV inoculation, suggesting potential use as detectors of SV in cell-based biosensor paradigm. These studies also provide the rationale, time-scale, and phenotypic correlates for further studies with gene expression arrays.

Animals↗
PubMed1988

A sensitive method for the identification of uncharacterized viruses related to known virus groups: hepadnavirus model system.

Amino acid sequence similarity of the reverse transcriptases encoded by retroviruses and hepadnaviruses was first reported by Toh, H., Hayashida, H. & Miyata, T. (1983) Nature (London) 305, 827-829. The regions of similarity extend over a small number of amino acids and require the introduction of gaps through the open reading frame. By using an octapeptide region as the sole criterion for "taxonomic" classification, we have grouped the oncoviruses into two distinct categories and the lentiviruses and hepadnaviruses into two additional groupings. This classification suggests that murine and feline leukemia viruses may be more closely related to the viruses that are associated with leukemia in primates and cattle than had been appreciated. We have exploited a portion of this region because of the minimal translational codon degeneracy of the conserved residues. Unique oligonucleotides from this region have been designed and used in the primer-directed in vitro DNA amplification of the hepadnaviruses as a model system. In addition, mixtures of oligonucleotides with various sequences but of the same length were demonstrated to be efficient primers. The amplification procedure enabled dramatic increases in sensitivity and coincident detection of mammalian and avian genomes. This approach will be a valuable tool to detect and characterize members of viral groups. In addition, since short stretches of similarity have been frequently identified in related but distinct genes, such an approach could prove a valuable asset to molecular studies in general.

Base Sequence↗
PubMed1988

An overview of retrovirus replication and classification.

This introductory chapter has presented an overview of how retroviruses replicate and how they are classified within the family Retroviridae. The genomic structure of retroviruses, so reminiscent of bacterial transposons and other similar genetic elements, and reverse transcriptase, which leads to the reverse flow of genetic information from RNA to DNA, are responsible for many of the properties of these viruses which make them both fascinating and important as causes of cancer and other diseases. The requirement for integration shared by most retroviruses leads directly to most of the phenomena resulting from their interaction with target cells. Certainly latency, at the level of the organism, is one such property relevant to how we think of vaccines and therapeutic reagents. The ability of retroviruses to acquire oncogenes from cellular DNA has greatly facilitated our understanding of the genetics of neoplasia. Additionally, the use of retroviral vectors to introduce new genes into genetically defective animals is a consequence of the genetic organization of retroviruses. Classification of viruses at the species level is difficult for several reasons. In particular, viruses do not sexually reproduce in any conventional sense, and it is difficult to identify a population of virions which make up a genetically distinct pool. Thus, the definition of individual species is often controversial and is not necessarily aided by the criteria used to define larger phylogenetic groups. In the latter case, retroviruses have distinctive morphological and biochemical features which allow their classification at the family, subfamily, genus, and subgenus levels. Additional classification occurs by accounting for factors such as host range, cross neutralization, ability to compete in interspecies radioimmunoassays, and genetic homology detected by hybridization under conditions of relaxed stringency. Direct comparison of nucleotide sequences offers the hope that mathematical criteria will be developed that can define the level of differences characteristic of individual species, genuses, and subfamilies.

Alpharetrovirus↗
PubMed1964

BLUE-GREEN ALGAL VIRUS LPP-1: PURIFICATION AND PARTIAL CHARACTERIZATION.

The blue-green algal virus LPP-1 was concentrated by ultrafiltration and purified by density-gradient and differential centrifugation. The virus contains DNA and has a sedimentation coefficient of 548S. Electron micrographs of purified viral preparations show that the polyhedral particles have short tails, which are approximately one-fourth as long as the diameter of the head. Data presented in this report indicate that the blue-green algal virus more closely resembles bacteriophages than viruses infecting higher plants.

Bacteriophages↗
PubMed1976

[Classification and infectiousness of chronic hepatitis B, defined by the Dane particle in the blood and virus components in the liver].

55 HBAg seropositive patients with chronic hepatitis B selected from a total of 217 liver biopsies were studied for the presence of HBcAg and HBsAg in the liver tissue and of Dane particles in blood by immunofluorescence and electron microscopy. Among 27 patients with non-aggressive chronic inflammation the following constellations were found: a) 19 patients (13 with nonspecific reactive hepatitis, 6 with chronic persistent hepatitis) had isolated HBsAg expression in the tissue (HBs type) and of these only 2 had rare Dane particles; b)4 patients (all with histologically very active chronic persistent hepatitis) with focal HBc- and HBsAg tissue expression (HBc+s type) and detectable Dane particles in blood; c)4 patients (1 with nonspecific reactive, 3 with chronic persistent hepatitis) with generalized HBcAg (and focal HBsAg) expression (HBc type) and multiple Dane particles in blood. Among 22 patients with aggressive inflammation (19 with chronic aggressive, 3 with "hippie"-hepatitis) focal HBcAg tissue expression (HBc+s type) was found in 17 cases and absence of HBcAg in 5 (3 with focal HBsAg, 2 completely negative by immunfluorescence), all 22 associated with Dane particles in blood, however. In a group of 6 immunosuppressed kidney transplant recipients exhibiting a high concentration of Dane particles in blood 5 patients had generalized HBcAg tissue expression (HBc type) in association with non-aggressive inflammation (1 nonspecific reactive and 4 chronic persistent hepatitis). One patient had chronic aggressive hepatitis in conjunction with focal HBcAg expression (HBc+s type). The consistent association of detectable HBcAg formation in the liver and presence of supposedly infectious Dane particles in blood has a bearing on the evaluation and classification of chronic hepatitis B. On the basis of a positive focal (HBc+s type) or generalized HBcAg tissue demonstration (HBc type and/or the direct identification of Dane particles in blood, discrimination of possibly highly infectious forms from those of low or even no infectivity has been rendered possible. This duality applies mainly to clinically and histologically benign non-aggressive forms of hepatitis presenting with a carrier state or chronic persistent hepatitis. On the basis of these and earlier findings a hypothetical concept of chronic hepatitis is presented which possesses proven diagnostic and prognostic applicability to routine liver biopsies. It is also capable of shedding new light on contradictory findings in the literature and serving as a basis for prospective epidemiologic studies.

Antilymphocyte Serum↗
PubMed1995

Hodgkin's disease as an indicator of AIDS.

Hodgkin's disease (HD) is not currently included within the Centers for Disease Control (CDC) classification system for AIDS. Upon HD diagnosis, HIV(human immunosuppressive virus)-positive patients are generally found within Stages III or IV of the Ann Arbor HD classification system, already exacerbating the problem of treatment. In contrast, HIV-negative patients diagnosed with HD are generally found within Stages I or II. Epidemiology and the presence of secondary lymphomas, opportunistic infections, or aggressive pathologies, accompanied by low survival rate and timing of HD diagnosis suggest that HD should be included among conditions indicating AIDS manifestation.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Phylogenetic analysis of primate foamy viruses by comparison of pol sequences.

The relationship between primate foamy viruses was determined by comparing a 425-bp DNA segment obtained by PCR using primers homologous to highly conserved portions of the pol gene. The phylogenetic tree of 14 foamy viruses investigated reflects the relationship between their host species: A cluster of Asian Old World monkey foamy viruses including simian foamy virus (SFV) prototypes 1 and 2 (isolated from Macaca cyclopsis) is separated from African Old World foamy viruses including prototype SFV-3 and SFV-3 strain LK-3 (isolated from African green monkeys, Cercopithecus aethiops). These two clusters of Old World monkey foamy viruses are more distantly related to a cluster of ape and human foamy viruses including prototypes SFV-6, SFV-7, SFV cpz (all isolated from chimpanzees), and human foamy virus (HFV). The New World prototype SFV-8 (isolated from a spider monkey, Ateles sp.) is distinct from the Old World cluster. Our own foamy virus isolates from a rhesus monkey (Macaca mulatta) and an African green monkey were grouped to the Asian or the African Old World monkey foamy virus cluster, respectively. The foamy virus sequences obtained from lymphocytes of two humans, one exposed to African green monkeys and the other to cultured HFV, were compared. The first sequence was closely related to the African Old World monkey foamy virus cluster, whereas the second was identical to HFV, except for a single mismatch. We conclude that limited sequencing of amplified DNA is a powerful tool for classification as well as molecular epidemiology of foamy viruses.

Animals↗