Interferon inducers: general survey and classification.
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Anti-Bacterial Agents↗
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[Histopathological characteristics and clinical significance of New Inuyama Classification in chronic hepatitis B].
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Biomarkers↗
[Study of the physicochemical properties, morphology and morphogenesis of the CHF-Congo group arboviruses for the purpose of determining the taxonomic position of these agents in the system of modern classification].
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Arboviruses↗
A comparison of six cypovirus isolates by cross-hybridisation of their dsRNA genome segments.
Genetic relationships between the genome segments of six cypovirus (CPV) isolates were analysed by RNA cross-hybridisation. These included three type 1 viruses and single isolates of types 2, 5 and 12, which collectively are identical to those previously compared by serology and electrophoresis [Mertens et al. (1989), J Gen Virol 70: 173-185]. Since only genome segment 10 of three cypovirus types and segments 8 and 9 of a single virus strain (of type 1) have currently been sequenced, this initial study provides some additional information on sequence variation/similarity in each of the ten genome segments. The RNA of the type 1 viruses showed high levels of cross-hybridisation. Significant but much lower levels of cross-hybridisation were detected between type 1 and the related type 12 CPV. However, only very low levels of cross-hybridisation were detected between the other pairs of viruses. Apart from evidence of a slightly higher level of sequence similarity between the largest segments, the RNA sequence appeared to vary uniformly across the whole genome. There was no evidence for any type specific RNA sequences restricted to individual genome segment(s). The sequence variation, reflected in the levels of RNA sequence similarity and cross hybridisation, correlates well with serological data, showing large differences between CPV types and supports the continued use of electropherotype as one of the 'species parameters' for the classification of cypoviruses.
Animals↗
Spatiotemporal patterns of Rift Valley fever virus in Africa: a retrospective genomic epidemiology and phylodynamic modelling study.
BACKGROUND: Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen causing outbreaks in humans and ruminants across Africa and the Arabian Peninsula. Originally restricted to the Great Rift Valley, RVFV has expanded geographically, prompting its classification by WHO as a pathogen of pandemic potential. We investigated the evolutionary and spatial dynamics of RVFV across Africa. METHODS: We used genomic data generated at the International Livestock Research Institute Nairobi genomic laboratory (BioProject PRJNA1106221) and combined with publicly available datasets retrieved from the National Center for Biotechnology (NCBI) GenBank nucleotide database. In retrieving RVFV genome sequences from the NCBI GenBank, we applied the search terms "Rift Valley fever virus segment L AND 6404[SLEN]", "Rift Valley fever virus segment M AND 3885[SLEN]", and "Rift Valley fever virus segment S AND 1520:1690[SLEN]" for L (Large), M (Medium), and S (Small) segments, respectively. For sequences without additional spatiotemporal information, we searched PubMed to extract the associated sequence metadata. We performed molecular clock analysis, phylogenetic inference, phylodynamic modelling (continuous phylogeographic reconstruction), and landscape phylogeography on the three RVFV genome segments (L, M, and S). We aimed to assess evolutionary rates, dispersal patterns, and environmental drivers. Focus was placed on lineage C, the most widely distributed variant. FINDINGS: The global dataset used in this study consisted of large (n=236), medium (n=237), and small (n=247), which were further filtered to exclude potential reassortants and vaccine strains. Genome sequences retrieved from NCBI GenBank database comprised large (n=180), medium (n=184), and small (n=202). The genome sequences from retrospective human and livestock isolates comprised large (n=56), medium (n=53), and small (n=45) collected in Burundi (2018), Kenya (2007, 2018, 2019, 2021, and 2022), and Rwanda (2018 and 2022). Our dataset revealed that RVFV exhibited low overall genetic diversity. Lineage C, however, showed evidence of active evolution, with substitution rates ranging from 3·58 × 10-4 to 9·76 × 10-4 substitutions per site per year. This lineage probably originated in Zimbabwe in the mid-1970s and has since expanded across eastern and southern Africa. Phylogeographic reconstructions revealed rapid spread, with diffusion coefficients exceeding 50 000 km2 per year. INTERPRETATION: Lineage C appears capable of establishing endemic transmission in new regions, with ongoing diversification observed during interepidemic periods. These observations reinforce the value of continuous genomic surveillance, particularly during cryptic transmission phases when adaptive mutations might emerge. Although further evidence is needed, observed trends in climate variability and land-use change point to the potential benefit of targeted surveillance in settings that could be at increased risk, including urban centres and wetlands. FUNDING: This work was supported by the German Federal Ministry for Economic Cooperation and Development, the Rockefeller Foundation, and the Africa Centres for Disease Control and Prevention.
Rift Valley fever virus↗
A novel method for pestivirus genotyping based on palindromic nucleotide substitutions in the 5'-untranslated region.
A simple and practical method was developed for pestivirus genotyping based on analysis of the secondary structures in the 5'-untranslated region (UTR). Three stable stem-loop structures, V1, V2 and V3, predicted by computer in the 5'-UTR, included strictly conserved consensus base-pairings which are shared by all the genotypes of pestivirus or are characteristic to each genotype of pestivirus. On the basis of the palindromic nucleotide substitution at the secondary structural level, six genotypes have been identified among pestivirus strains, irrespective of the cytopathic and non-cytopathic biotypes. They are genotypes Ia, Ib, Ic and II in bovine viral diarrhea virus, genotype III in border disease virus, and genotype IV in classical swine fever virus. The stable stem-loop structures, which were maintained by palindromic nucleotide substitutions in the stem region, may represent references for the classification and identification of pestivirus species and/or genotypes.
Animals↗
Fusion protein predicted amino acid sequence of the first US avian pneumovirus isolate and lack of heterogeneity among other US isolates.
Avian pneumovirus (APV) was first isolated from turkeys in the west-central US following emergence of turkey rhinotracheitis (TRT) during 1996. Subsequently, several APV isolates were obtained from the north-central US. Matrix (M) and fusion (F) protein genes of these isolates were examined for sequence heterogeneity and compared with European APV subtypes A and B. Among US isolates the M gene shared greater than 98% nucleotide sequence identity with only one nonsynonymous change occurring in a single US isolate. Although the F gene among US APV isolates shared 98% nucleotide sequence identity, nine conserved substitutions were detected in the predicted amino acid sequence. The predicted amino acid sequence of the US APV isolate's F protein had 72% sequence identity to the F protein of APV subtype A and 71% sequence identity to the F protein of APV subtype B. This compares with 83% sequence identity between the APV subtype A and B predicted amino acid sequences of the F protein. The US isolates were phylogenetically distinguishable from their European counterparts based on F gene nucleotide or predicted amino acid sequences. Lack of sequence heterogeneity among US APV subtypes indicates these viruses have maintained a relatively stable population since the first outbreak of TRT. Phylogenetic analysis of the F protein among APV isolates supports classification of US isolates as a new APV subtype C.
Amino Acid Sequence↗
Cutaneous manifestations of early human immunodeficiency virus exposure.
After demonstrating antibodies to the human immunodeficiency virus (HIV), two hundred patients were interviewed and given a complete cutaneous and mucous membrane examination. By means of the Walter Reed Staging Classification System for HIV infection, 155 patients were classified as having Walter Reed stage 1A-2A (WR1A-WR2A) infection. The prevalence of seborrheic dermatitis in this group was 36%. There were no other significant cutaneous findings in the WR1A-WR2A patient population.
Acquired Immunodeficiency Syndrome↗
Phenotypic and cytotoxic characteristics of peripheral T-cell and NK-cell lymphomas in relation to Epstein-Barr virus association.
AIMS: We investigated the phenotypic and cytotoxic characteristics of different types of peripheral T-cell and NK-cell lymphomas and correlated the findings of cytotoxic phenotype with Epstein-Barr virus (EBV) association. METHODS AND RESULTS: Eighty cases of peripheral T-cell and NK-cell lymphomas, classified according to the REAL classification, were investigated for cytotoxic phenotype (by studying T-cell intracellular antigen-1 (TIA-1) expression immunohistochemically) and EBV association (by in situ hybridization for EBV-encoded small non-polyadenylated RNAs), and the results were correlated with the specific clinicopathological types and the immunophenotype with special emphasis on CD56 expression and CD4/CD8 status. Overall, 39/80 cases (49%) expressed TIA-1. Angiocentric lymphoma (23/24 cases; 96%), aggressive NK-cell leukaemia ('large granular lymphocyte (LGL) leukaemia') (3/3 cases; 100%), intestinal T-cell lymphoma (5/6 cases; 83%) and anaplastic large cell lymphoma (4/6 cases; 67%) were the major subtypes showing a cytotoxic phenotype. Only four of the 27 cases (15%) of peripheral T-cell lymphoma, unspecified, were TIA-1+, while all the seven cases of angioimmunoblastic T-cell lymphoma, six cases of mycosis fungoides and one case of adult T-cell lymphoma/leukaemia were TIA-1-. CONCLUSIONS: Within the group of peripheral T-cell and NK-cell lymphomas, angiocentric lymphoma, aggressive NK-cell leukaemia ('LGL leukaemia'), intestinal T-cell lymphoma and anaplastic large cell lymphoma are the major subtypes displaying a cytotoxic phenotype. The relationships between the cytotoxic phenotype and EBV association, CD56 expression or CD4/CD8 status are secondary to the relationship between cytotoxic phenotype and specific lymphoma subtype.
Adult↗
Presence of restricted killer immunoglobulin-like receptor repertoire and monoclonal T-cell receptor gamma rearrangement as evidence of mixed NK/T-cell differentiation in a subset of sinonasal lymphomas.
Most sinonasal lymphomas have a restricted killer immunoglobulin-like receptor (KIR) repertoire without a monoclonal T-cell receptor-gamma (TCR-gamma) rearrangement, implying an NK lineage. However, the lineage assignment of sinonasal lymphoma with a monoclonal TCR-gamma rearrangement is unclear because of its mixed NK/T phenotype. The possibility of a mixed NK/T lineage arises with the discovery of T cells with NK features, such as KIR(+) T cells or Valpha24(+) NKT cells. The former might transform into a T-cell lymphoma with both a monoclonal TCR-gamma rearrangement and a restricted KIR repertoire; the latter might give rise to a T-cell lymphoma with a monoclonal Valpha24 rearrangement and possibly a restricted KIR repertoire. To identify such mixed-lineage lymphomas, we undertook a survey of 15 consecutive sinonasal lymphomas and found six with both a restricted KIR repertoire and a monoclonal TCR-gamma rearrangement, consistent with KIR(+) T-cell lymphomas. Among these six cases, four female CD56(-)/CD44(-)/CD8(-)/CD45RO(+)/CD45RA(-) cases constituted a distinct group with a better prognosis than the rest of the male cases of sinonasal lymphomas. None of the six cases had a monoclonal Valpha24 repertoire, thus excluding a derivation from NKT cells. The predominance of KIR(+) T cells that normally function in chronic viral infections over Valpha24(+) NKT cells that typically recognize glycolipid antigens is consistent with the known association of Epstein-Barr virus infection with sinonasal lymphoma. The demonstration of mixed lineage in a mature lymphoid neoplasm is unusual and echoes the World Health Organization classification that placed NK-cell and T-cell lymphomas in a mixed group.
Base Sequence↗
Alignment of capsid protein VP1 sequences of all human rhinovirus prototype strains: conserved motifs and functional domains.
An alignment was made of the deduced amino acid sequences of the entire capsid protein VP1 of all human rhinovirus (HRV) prototype strains to examine conserved motifs in the primary structure. A set of previously proposed crucially important amino acids in the footprints of the two known receptor molecules was not conserved in a receptor group-specific way. In contrast, VP1 and VP3 amino acids in the minor receptor-group strains corresponding to most of the predicted ICAM-1 footprint definitely differed from those of the ICAM-1-using major receptor-group strains. Previous antiviral-sensitivity classification showed an almost-complete agreement with the species classification and a fair correlation with amino acids aligning in the antiviral pocket. It was concluded that systematic alignment of sequences of related virus strains can be used to test hypotheses derived from molecular studies of individual model viruses and to generate ideas for future studies on virus structure and replication.
Capsid↗
Nutritional guidelines for persons infected with the hepatitis C virus: a review of the literature.
Hepatitis C virus (HCV) is one of the leading causes of chronic liver disease. It was first identified in 1989, as being distinct from hepatitis A and hepatitis B. The HCV does not attack the immune system, but rather causes an inflammatory reaction that is localized within the liver, involving the entire organ. About 80% of patients with acute hepatitis C will develop chronic HCV, of which about 20-30% will progress to cirrhosis and its consequences, over 10-20 years. After 20-40 years, a smaller proportion of patients with chronic disease will develop hepatocellular carcinoma. The course and outcome of the disease vary considerably. In some individuals, spontaneous remission occurs over a few years; in others, the disease is more severe, progressing to cirrhosis and end-stage liver disease. Despite biochemical and pathological confirmation of the diagnosis, patients are often asymptomatic for many years. Hepatic failure occurs late in the disease. Factors suggesting a poor prognosis include high serum transaminase levels, active cirrhosis on liver biopsy, and an increased viral load (HCV RNA), as well as associated medical conditions such as alcoholic liver disease, hepatitis B viral (HBV) infection, or human immunodeficiency virus (HIV). Nutrition has been recognized as a prognostic indicator in patients with chronic liver failure. However, standardized approaches for the diagnosis and classification of malnutrition in this population have not been consistently applied before implementing nutrition intervention. Common criteria for the assessment of malnutrition, weight and body mass index (BMI) for example, do not give accurate data in patients with chronic liver disease, complicated by ascites and edema. In addition, the chronic inflammatory reaction of liver failure progresses slowly, so that subtle nutritional deficits are not obvious at early stages of the disease. A review of the literature has been undertaken to identify current nutritional guidelines for patients with hepatitis C as well as chronic hepatitis.
Acute Disease↗
[Problem of chronic hepatitis (classification, pathogenesis and treatment].
Update information is added to classification of chronic hepatitis. A new form--chronic lobular hepatitis is described as well as characteristic features of immune response to hepatitis B virus (HBV). The findings enable the authors not only to relate autoimmune abnormalities to HBV infection, but to consider them an essential component of this infection. The leading role in pathogenesis of viral hepatic lesions is played by cellular immunity. A sound subpopulation analysis of immunocompetent blood cells was carried out for chronic active hepatitis and hepatic cirrhosis in correlation with HBsAg. It is emphasized that a biological cycle of HBV development determines the type and power of the macroorganism immune response and should be allowed for when designing policy of treatment of chronic hepatic viral diseases. Criteria are proposed for deciding on immunomodulators and immunodepressants for chronic viral and autoimmune hepatitis.
Autoimmune Diseases↗
[Carcinomas of the nasopharynx. Relationship between histological type and anti-Epstein-Barr virus serology (author's transl)].
This study was aimed at the comparison of values of anti-Epstein-Barr virus serology in different groups of patients suffering from carcinoma of the nasopharynx (NPC), classified according to histological type defined by the new classification of the WHO. A group of patients with other tumours of the upper respiratory and digestive tract was used as a control. Antibody levels were high in patients with undifferentiated carcinomas whilst they were low in the controls. In patients with differentiated carcinomas antibody levels were most often equivalent to those of the controls, even though high values were sometimes seen. These findings would appear to offer evidence that the new histological classification of NPC is well founded, and to a certain extent reflect the epidemiological, clinical and therapeutic classifications already seen for these two types of carcinoma.
Animals↗
[New contributions to the etiology of insulin-dependent diabetes (author's transl)].
The present studies on the possible factors that can be implicated in the etiopathogenesis of diabetes are reviewed. The association between insulin-dependent diabetes and certain specifications of the HLA system are commented on, as well as the experimental studies and the clinical observations which indicate the possible relationship between this disease and some viruses. The role played by autoimmunity is thoroughly discussed, specially the significance of anti-pancreatic islet antibodies. Finally, new pathogenic theories and classifications of the disease are proposed.
Autoantibodies↗
[Parvovirus B19-induced arthritis/arthropathy--an important differential diagnosis of chronic polyarthritis].
INTRODUCTION/AIMS: The differential diagnosis of rheumatoid arthritis (RA) and parvovirus-B19-induced arthritis/arthropathy (PBA) can be difficult, but is of importance because of the different therapeutic implications. The purpose is to describe characteristic features serving to differentiate between chronic PBA and RA, based on 6 personal cases and the literature. METHODS/PATIENTS: 6 patients presenting with acute (3 cases) or chronic PBA (3 cases) over the last 5 years are described. RESULTS/CONCLUSIONS: The demonstration of anti-parvovirus-B19-immunoglobulins (Ig)M in addition to anti-parvovirus-B19-IgG is the most important diagnostic finding. Measurement of IgM must be done within the first months after onset, as it disappears later on. Furthermore, history of disease (exposure, prodromi and acute onset of arthritis), clinical examination (rash) and further investigations (normal ESR and CRP, typical hematologic findings, examination of synovial tissue and fluid without inflammatory changes, demonstration of the genome of parvovirus B19 by polymerase chain reaction, no erosions on radiographs) support the diagnosis of PBA. 2 of the 3 patients with chronic PBA fulfilled the criteria for classification of RA. Therapeutic approaches in PBA are discussed. In contrast to the favourable effect in RA, immunosuppressive agents may prolong persistence of virus and disease in PBA.
Adult↗
The value of lymph node histology in human immunodeficiency virus related persistent generalized lymphadenopathy.
Histological changes in lymph nodes were evaluated in a prospective study of 124 homosexual men who presented with generalized lymphadenopathy. The histological changes were classified according to a classification system with three stages. HIV antibodies were present in 88% of the patients. The finding of one of the three histopathological stages was highly indicative--although not absolutely pathognomonic--for HIV infection. The subsequent course of HIV infection after biopsy was significantly correlated to the histopathological changes, but it was not possible to evaluate if the biopsy added new information to that already available. Among the group of HIV infected, immediate clinical consequences of lymph node biopsy were not observed (95% confidence limits 0-3.3%). In a retrospective investigation of 123 consecutive AIDS patients, it was found that lymph node histopathology had been able to identify secondary infections and neoplasms among 10%. It is concluded that lymph node biopsy is indicated in the HIV infected patients with unexplained generalized symptoms or with atypical enlargement of the lymph nodes. The prognostic significance of lymph node histology compared to other prognostic parameters of HIV infection, remains to be determined.
AIDS-Related Complex↗
Molecular and morphological evidence for type B retrovirus (oncornavirus) expression in human mammary carcinoma. An overview using scanning electron microscopy, immunoperoxidase staining, and transmission electron microscopy.
Approximately 45% of human mammary carcinoma cases express an antigen which cross reacts in formalin fixed tissues with antiserum prepared against the purified 52,000 molecular weight structural glycoprotein (gp52) of mouse mammary tumor virus (MMTV). Breast carcinoma immunoperoxidase marking is abolished by antiserum adsorption with MMTV. Adsorption with murine leukemia virus failed to block immunoperoxidase marking. No correlation was seen in the cases analyzed between gp52-like antigen expression and family history of mammary carcinoma, age, or pathological classification. The evidence linking an oncornaviral agent in human mammary carcinoma is reviewed with respect to the structure and biology of a known etiological agent, MMTV, in murine mammary cancer. The potential role of SEM in amplifying the surface area available for analysis in malignant and premalignant human breast epithelia is considered.
Antigens, Neoplasm↗