[The classification of viral pneumopathies among acute pneumopathies].
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Acute Disease↗
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[Etiology and classification of cardiomyopathies].
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Cardiomyopathies↗
Preliminary classification of nonmalignant B cell proliferation in Sjögren's syndrome: perspectives on pathobiology and treatment based on an integrated clinico-pathologic and molecular study approach.
A classification of nonmalignant lymphoproliferation in Sjögren's syndrome is presented, based on the results of international meetings regarding Sjögren's syndrome-associated lymphomagenesis and on our results of a clinico-pathologic and molecular study and long-term follow-up in well-characterized patients. Sjögren's syndrome pathobiology has similarities to hepatitis C virus-related B-cell lymphoproliferation. Antigen stimulation with the preferential expansion of rheumatoid factor-positive clones and specific immunoglobulin gene expression and recombination represent key biologic events in lymphoproliferation. This classification is based on the coupling of molecular and histological studies and may result in more selective treatment approaches.
Adult↗
Genetic and physiological characterization of temperature-sensitive mutants of bluetongue virus.
Complementation studies were carried out, using temperature-sensitive (t-s) mutants of blue-tongue virus (BTV). The results proved to be inconclusive as only low indices of complementation were obtained. No discrepancy was found between the previous classification of these mutants in 6 recombination classes and the complementation data recored. In general, the t-s mutants require a latent growth period of 16-20 h at 28 degrees C and maximum titres can be demonstrated 40-48 h post-infection. One mutant, (F211), however, consistently had a growth lag phase of 32 h. Mutants of the 6 recombination groups were further classified into 2 groups by temperature-shift studies. One calss of mutants expressed their t-s lesion prior to 24 h and the other class only after 24 h post-infection. Mutant F73 was found to be defective in its ability to synthesize ssRNA at a late stage in the replication cycle at the non-permissive temperature.
Bluetongue virus↗
Imbroglios of viral taxonomy: genetic exchange and failings of phenetic approaches.
The practice of classifying organisms into hierarchical groups originated with Aristotle and was codified into nearly immutable biological law by Linnaeus. The heart of taxonomy is the biological species, which forms the foundation for higher levels of classification. Whereas species have long been established among sexual eukaryotes, achieving a meaningful species concept for prokaryotes has been an onerous task and has proven exceedingly difficult for describing viruses and bacteriophages. Moreover, the assembly of viral "species" into higher-order taxonomic groupings has been even more tenuous, since these groupings were based initially on limited numbers of morphological features and more recently on overall genomic similarities. The wealth of nucleotide sequence information that catalyzed a revolution in the taxonomy of free-living organisms necessitates a reevaluation of the concept of viral species, genera, families, and higher levels of classification. Just as microbiologists discarded dubious morphological traits in favor of more accurate molecular yardsticks of evolutionary change, virologists can gain new insight into viral evolution through the rigorous analyses afforded by the molecular phylogenetics of viral genes. For bacteriophages, such dissections of genomic sequences reveal fundamental flaws in the Linnaean paradigm that necessitate a new view of viral evolution, classification, and taxonomy.
Bacteriophages↗
A multiplex PCR assay able to simultaneously detect Torque teno virus isolates from phylogenetic groups 1 to 5.
Torque teno virus (TTV) is a circular, single-stranded DNA virus that chronically infects healthy individuals of all ages worldwide. TTV has an extreme genetic heterogeneity which is reflected in its current classification into five main phylogenetic groups (1-5). Using specific PCR assays, it has been shown that many individuals are co-infected with TTV isolates belonging to different phylogenetic groups. Here, a multiplex PCR assay was developed, using five recombinant plasmids. Each plasmid carried an insert of different size issued from a TTV isolate belonging to a different group. The assay was able to simultaneously amplify DNAs of TTV isolates belonging to all five phylogenetic groups. Multiplex PCR was then tested satisfactorily on DNAs extracted from 55 serum samples (47 health care workers and 8 AIDS patients). All individuals but nine were infected with at least one TTV isolate. Co-infection with multiple isolates was found in 29/47 (62%) health care workers and in 8/8 (100%) AIDS patients. A number of discrepancies were observed when results obtained with three thermostable DNA polymerases were compared. For example, four TTV phylogenetic groups were detected in a particular serum sample by using one of the three DNA polymerases, whereas the other two enzymes were able to detect only three TTV groups. However, none of the three enzymes used could be broadly considered to be more efficient than the others. Despite its limitations, the assay described here constitutes a suitable tool to visualize the degree of co-infection of a given population, avoiding time-consuming experiments.
Acquired Immunodeficiency Syndrome↗
Adult T-cell leukemia/lymphoma: a working point-score classification for epidemiological studies.
Adult T-cell leukemia/lymphoma (ATL) is a malignancy that occurs most frequently in south-western Japan and the Caribbean basin. The primary etiologic agent for this disease, human T-lymphotropic virus type I (HTLV-I), is endemic in these areas. Only a small percentage of individuals infected with HTLV-I develop ATL. The factors that determine the development of malignant disease as an outcome of HTLV-I infection in an individual are unknown. ATL is histopathologically heterogeneous and firm diagnosis is made on the contribution of clinical, laboratory and histopathologic features. The wide variety of laboratory assays available to geographically diverse populations has led to a need to standardize the criteria for determining the diagnosis of this disease for epidemiologic studies. This report summarizes current information regarding ATL and proposes a classification facilitating comparison of case series in geographically and ethnically different populations.
Adult↗
Respiratory viruses in the intensive care unit.
Respiratory viruses cause a number of clinical 'syndromes' in the intensive care unit with different viruses being able to produce similar clinical pictures. Our main presenting problems are upper airway (e.g. croup and tracheitis), lower airway with intrapulmonary shunt (e.g. bronchitis and pneumonia), lower airway with dynamic hyperinflation (e.g. bronchiolitis and wheeze) and control of breathing (e.g. apnoea). This pragmatic classification is used because it enables focus on the physiological abnormality needing treatment, and how best to deliver appropriate and adequate ventilator support. This review provides an overview of these syndromes and a more detailed account of respiratory syncytial virus, our most commonly diagnosed winter illness.
Child, Preschool↗
Influence of human immunodeficiency virus infection on hepatitis delta virus superinfection in chronic HBsAg carriers.
It is generally agreed that hepatitis B virus (HBV) replication is reduced by hepatitis delta virus infection (HDV) and augmented by human immunodeficiency virus (HIV) infection. However, the precise nature of the interactions between HBV, HDV and HIV is controversial. The aim of this study was to evaluate the impact of HIV infection on HBV and HDV replication, and on histological scores during delta virus superinfection in HDV-positive, chronic carriers of hepatitis B surface antigen (HBsAg). We studied 38 men and six women, 15 of whom were HIV-positive and all of whom had at least one marker of HDV infection. Serum hepatitis B e antigen (HBeAg), HBV DNA, HDV RNA, anti-delta antigen antibodies (anti-HD) IgM, anti-HD IgG and hepatitis delta antigen (HDAg) were tested for in the serum and liver, respectively; anti-hepatitis C virus (HCV) antibodies were detected using a second-generation recombinant immunoblot assay. Histological specimens were scored blindly according to Knodell's classification for periportal and intralobular necrosis, portal inflammation and fibrosis. HBV DNA was detected more frequently in the HIV-positive patients than in those who were HIV-negative (25 vs 0%; P = 0.01), while markers of HDV replication (serum anti-HD IgM, serum HDV RNA and liver HDAg) were as frequent in the HIV-positive patients (69%, 40% and 50%, respectively) as in those who were HIV-negative (75%, 52% and 30%, respectively; P > 0.05). By contrast, 31% of the HIV-positive patients were serum HDAg-positive compared to only 6% of the HIV-negative patients (P = 0.001). HDV antigenaemia and anti-HD antibodies usually fluctuated in the HIV-positive patients during follow-up. The mean Knodell score was similar in the HIV-positive (11.5 +/- 3.2) and HIV-negative (10.7 +/- 2) subgroups, as was the mean semi-quantitative index of hepatic necrosis, inflammation and fibrosis. Our results provide evidence that in HDV-positive patients: (1) HIV infection counters the inhibitory effect of HDV superinfection on HBV replication; (2) serum anti-HD IgM. HDV RNA and liver HDAg are not more frequent in HIV-positive than in HIV-negative patients, suggesting that HIV infection has no effect on HDV replication (although the significance of the increased frequency of HD antigenaemia remains unclear); (3) the histological severity of liver disease is not influenced by HIV status.
Adult↗
Non-condylomatous, perianal disease in homosexual men.
This retrospective study details the findings and outcome in 34 homosexual men, out of a total of 177 patients, who underwent surgery for non-condylomatous perianal disease over a 2-year period. Of 34 homosexuals 20 presented with anorectal sepsis compared with 11 of 79 heterosexual male patients (X2 = 24.07, P less than 0.001). Lesions included chronic intersphincteric abscess (eight patients), anal fistula (seven patients) and chronic intersphincteric abscess and fistula (five patients). Anal fissure occurred in 15 patients, anal ulcer in three, skin tags in six, haemorrhoids in two and Kaposi's sarcoma in one. Eight patients were human immunodeficiency virus (HIV) antibody negative, four were asymptomatic HIV antibody positive, 12 had symptomatic HIV infection using the Centers for Disease Control classification and in ten patients HIV status was unknown. Irrespective of the type of surgery performed, healing occurred within 6 weeks of operation in all HIV antibody negative patients, all asymptomatic HIV antibody positive and in only one of nine patients with symptomatic HIV infection. Eight of nine patients with symptomatic HIV infection failed to heal by this time (X2 = 8.98, P less than 0.05). These findings suggest that the prevalence of anorectal sepsis in homosexual men is high and that symptomatic HIV infection is an important determinant of progress after surgery.
Abscess↗
Prospective validation of serum CYFRA 21-1, beta-2-microglobulin, and ferritin levels as prognostic markers in patients with nonmetastatic nasopharyngeal carcinoma undergoing radiotherapy.
BACKGROUND: Patients with undifferentiated nasopharyngeal carcinoma (NPC) have elevated serum levels of CYFRA 21-1 (CYFRA), ferritin, and beta-2-microglobulin (beta2M) compared with healthy control individuals. The prognostic value of these markers has never been validated prospectively. METHODS: Paired serum samples from 160 patients with newly diagnosed, nonmetastatic, undifferentiated NPC were collected before radiotherapy (RT) and at 4-6 weeks after the completion of RT. Pre-RT and post-RT levels of serum CYFRA, ferritin, and beta2M were analyzed and correlated with overall survival (OS), progression-free survival (PFS), time to locoregional recurrence, (TLR) and time to distant recurrence (TDR). The results of pre-RT and post-RT plasma Epstein-Barr virus (EBV) DNA levels available from a previous study were included in a Cox regression model together with age, tumor (T) classification, and lymph node (N) classification. RESULTS: Sixty percent of patients had International Union Against Cancer Stage III-IV disease. At a median follow-up of 116 weeks (range, 37-239 weeks), 38 patients had disease progression. On multivariate analysis, pre-RT CYFRA and post-RT EBV DNA levels were independent predictors of poor OS, post-RT EBV DNA level and N classification predicted poor PFS and TDR; and only T classification predicted TLR. Patients who had pre-RT CYFRA levels > or = 1.5 U/mL were more likely to die (hazard ratio, 1.18; 95% confidence interval, 1.10-1.26) compared with patients who had pre-RT CYFRA levels < 1.5 U/mL. There were no associations between age, post-RT CYFRA levels and pre-RT or post-RT serum ferritin and beta2M levels, and the survival and recurrence rates on multivariate analysis. CONCLUSIONS: Serum CYFRA levels taken before RT predicted reduced survival in patients with nonmetastatic, undifferentiated NPC who underwent RT.
Adolescent↗
Elevated antibody titers against cytomegalovirus among patients with testicular cancer.
The epidemiology of testicular cancer (TC) has 2 distinguishing features. First, it has an unusual unimodal age-incidence curve which peaks about age 30, and decreases with increasing age. Second, risk of the disease has been consistently associated with a high standard of living inasmuch as it is a disease of young white men of generally higher social class in economically developed populations. These features suggest that risk may be related to relatively late age of exposure to common infectious agents resulting in damage to the developing testis. We evaluated this hypothesis in a serologic case-control study in which subjects were compared for both prevalence and level of antibody to the following agents: measles, mumps, rubella, varicella (VZV), herpes simplex (HSV), cytomegalovirus (CMV), toxoplasmosis, Chlamydia, and Mycoplasma hominis. The TC cases included 50 with seminoma, 50 with embryonal carcinoma, and 17 with other sub-classifications. There were 100 male controls of comparable age. No consistent differences were found for any of the non-herpes viruses. For VZV, cases generally had elevated titers, significantly so for the seminoma patients, relative risk (RR) = 6.3 (95% confidence interval, 3.0-13.3) adjusted for the titer distributions of HSV and CMV. For HSV, seminoma patients also had elevated titers, RR = 2.6 (1.0-6.4). The strongest association was with CMV. Patients had a higher prevalence rate than controls, RR = 2.0 (1.1-3.6), and a gradient of risk with titer level. Overall, those in the highest titer quartile had an RR of 4.9 compared to those with no antibody, with a significant trend (p = 0.0002). Since age at CMV infection is directly related to social class, these findings suggest that delayed exposure to CMV, resulting in a more severe infection, may be related to risk of TC. However, confounding by immune status of the cases or by other risk factors of TC could not be evaluated and may account for this observation.
Antibodies, Viral↗
Pathologic classification of focal segmental glomerulosclerosis.
Focal segmental glomerulosclerosis (FSGS) is defined as a clinical-pathologic syndrome manifesting proteinuria and focal and segmental glomerular sclerosis with foot process effacement. The pathologic approach to the classification of FSGS is complicated by the existence of primary (idiopathic) forms and multiple subcategories with etiologic associations, including human immunodeficiency virus (HIV)-associated nephropathy, heroin nephropathy, familial forms, drug toxicities, and a large group of secondary FSGS mediated by structural-functional adaptations to glomerular hyperfiltration. A number of morphologic variants of primary and secondary focal sclerosis are now recognized, including FSGS not otherwise specified (NOS), perihilar, cellular, tip, and collapsing variants. The defining features of these morphologic variants and of the major subcategories of FSGS are discussed with emphasis on distinguishing light microscopic patterns and clinical-pathologic correlations.
Disease Progression↗
Emerging infectious pathogens of wildlife.
The first part of this paper surveys emerging pathogens of wildlife recorded on the ProMED Web site for a 2-year period between 1998 and 2000. The majority of pathogens recorded as causing disease outbreaks in wildlife were viral in origin. Anthropogenic activities caused the outbreaks in a significant majority of cases. The second part of the paper develops some matrix models for quantifying the basic reproductive number, R(0), for a variety of potential types of emergent pathogen that cause outbreaks in wildlife. These analyses emphasize the sensitivity of R(0) to heterogeneities created by either the spatial structure of the host population, or the ability of the pathogens to utilize multiple host species. At each stage we illustrate how the approach provides insight into the initial dynamics of emergent pathogens such as canine parvovirus, Lyme disease, and West Nile virus in the United States.
Animal Diseases↗
Skeletal muscle involvement in HIV-infected patients.
Skeletal muscle involvement may occur at all stages of human immunodeficiency virus (HIV)-infection, and represents the first manifestation of the disease in some patients. There have been many controversies about the classification of myopathies related to HIV infection. We usually classify muscle involvement in HIV-infected patients in one of the following categories: (1) HIV-associated myopathy, a myopathy that meets the criteria for polymyositis in a majority of patients, and those for acquired nemaline myopathy in some; (2) zidovudine myopathy, a reversible mitochondrial myopathy; (3) the HIV-wasting syndrome and other AIDS-associated cachexias; (4) opportunistic infections and tumoral infiltrations of skeletal muscle; (5) vasculitic processes and iron pigment deposits. Immunohistology for major histocompatibility complex class I antigen and the histochemical reaction for cytochrome C oxidase are helpful in correctly classifying a myopathy as HIV polymyositis or zidovudine myopathy respectively. Studies of circulating levels and tissue expression of cytokines in HIV-infected patients have yielded new insights into the pathogenesis of the various AIDS-associated muscle disorders.
HIV Infections↗
[Does alcoholic chronic hepatitis exist?].
Alcoholic chronic hepatitis (ACH) can be considered as an independent nosological entity. This conclusion can be made basing on the literature devoted to the mechanisms of ethanol effects on the liver and clinicomorphological features of hepatic ethanol damage. ACH should be included into the new 1994 International classification of chronic hepatitis. Special attention is paid to a higher incidence of combined liver damage induced by alcohol and hepatotropic viruses, especially by hepatitis C virus. Combined virus-alcoholic liver damage will become, in the author's opinion, one of the most important hepatology problems in the coming millenium.
Ethanol↗
[Primary effusion lymphoma associated with type-8 human herpes virus infection].
Primary Effusion Lymphoma is an unusual entity and it has been described as a subset associated with human herpes virus 8 infection in homosexual males with AIDS. Its inclusion as a new entity in the Revised European-American Lymphoma Classification has been recommended. The case in which it is presented is a 47-year-old man, diagnosed with AIDS two years ago, who came with Kaposi's sarcoma. Nowadays, he has a right pleural effusion and a thoracentesis has been carried out. We obtain 10 ml of haemorrhagic fluid which is processed by standard methods. The morphologic study reveals a non-Hodgkin's lymphoma of high-grade. The immunophenotypic study shows a lymphoid neoplasm of indeterminate lineage and high proliferation index. It confirms the HHV-8 in the neoplastic cells by PCR. The diagnosis is a non-Hodgkin's lymphoma of high-grade compatible with Primary Effusion Lymphoma.
Herpesviridae Infections↗
Some trends of research in the domain of viral neuroinfections approached in the "Stefan S. Nicolau" Institute of Virology.
The main directions of research in the field of viral neuroinfections approached during 35 years in the Institute of Virology are briefly outlined. After some considerations on terminology and on the classification of viral encephalitides, mention is made of the studies in the domain of herpes infections, rabies, meningitis, encephalitis and slow virus infections of the central nervous system (subacute sclerosing panencephalitis, multiple sclerosis, amyotrophic lateral sclerosis, Creutzfeldt-Jakob disease, etc.).
Academies and Institutes↗