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At least 757 records · Page 42Linked to original sources
PubMed1965

ONTOGENESIS OF HUMAN SMALLPOX VIRUS.

THE VEGETATIVE STAGE OF DEVELOPMENT OF THE HUMAN SMALLPOX VIRUS IS DESCRIBED AS BEING COMPRISED OF FOUR SUCCESSIVE PERIODS: "without membrane" period; "open-cavity" period; "single-cavity" period; and "double-cavity" period. This classification is based on the organization of the virus membranes. This paper presents a description of the changes in virus structure during each period. It shows the strict sequence of morphological continuity and succession of differentiation of viral components. The most important stage of the development, the differentiation of virus nucleoid, takes place in the virus cavity morphologically isolated from the cellular milieu and limited originally by the external membrane of the virus and then by the second one, the primary membrane of the nucleoid. Osmiophilic fibrils 20 to 25 A wide, which fill the cavity of a mature nucleoid, become clearly evident after staining with uranyl acetate and are revealed only at the end of the last or double-cavity period. The main features of the developmental cycle of human smallpox virus may probably be characteristic of certain other groups of viruses.

Cell Biology↗
PubMed2001

Latent intracellular Epstein-Barr Virus DNA demonstrated in ocular posttransplant lymphoproliferative disorder mimicking granulomatous uveitis with iris nodules in a child.

A case of intraocular posttransplant lymphoproliferative disorder (PTLD) is described in a 9-year-old female who underwent orthotopic liver transplantation at the age of 18 months. The prevalence of ophthalmic involvement in PTLD can be expected to rise with the increasing number of major organ transplantations, as well as improved survivorship. Children are particularly at risk for this posttransplant complication because they are usually seronegative for the Epstein-Barr virus (EBV) prior to transplant. Accurate diagnostic classification of PTLD to include confirmation of EBV infection carries significant therapeutic and prognostic implications.

Child↗
PubMed1994

Analysis of the hepatitis C virus genome in patients with anti-LKM-1 autoantibodies.

Hepatitis C virus genotypes have been characterized in 22 patients with anti-LKM-1 positive chronic hepatitis C. Following the Simmonds classification, 77% of patients were infected by hepatitis C virus genotype 1, 18% by genotype 2 and 5% by genotype 3, thus excluding the association of the autoimmune reaction with a particular viral type. Prevalences of genotype 1 and 2 were significantly different from those obtained in 79 patients with chronic hepatitis C who were negative for anti-LKM-1, as these were more rarely infected by genotype 1 and more frequently by genotype 2. Clinical findings of anti-LKM-1 positive patients were similar in all three groups. Sequence analysis of the amplified 5'UTR provided identification of peculiar and identical nucleotide substitutions in two out of four patients with genotype 2. The analysis of the secondary structure of this region showed that the observed nucleotide mutations increased the stability of the stem formed in this position.

Adolescent↗
PubMed2000

Taxonomy of the caliciviruses.

The International Committee on Taxonomy of Viruses (ICTV) has recently approved several proposals submitted by the present Caliciviridae Study Group. These proposals include the division of the family into 4 new genera designated Lagovirus, Vesivirus, "Norwalk-like viruses (NLVs), and "Sapporo-like viruses (SLVs); the latter 2 genera were assigned temporary names until acceptable names can be determined by the scientific community. The genera have been further divided into the following species: Feline calicivirus and Vesicular exanthema of swine virus (genus Vesivirus), Rabbit hemorrhagic disease virus and European brown hare syndrome virus (genus Lagovirus), Norwalk virus (genus NLV), and Sapporo virus (genus SLV). In addition, the ICTV approved a proposal to remove the hepatitis E virus from the Caliciviridae into an "unassigned classification status.

Animals↗
PubMed2003

Epstein-Barr virus (EBV)-related oral squamous cell carcinoma in Okinawa, a subtropical island, in southern Japan--simultaneously infected with human papillomavirus (HPV).

Up to now, many authors have reported on the EBV infection and its carcinogenic importance in undifferentiated nasopharyngeal carcinoma (WHO classification, type III), but the infection of the virus in well differentiated oral squamous cell carcinoma has not been well described. We introduce the EBV-related well differentiated oral squamous cell carcinomas in Okinawa, a subtropical island in the southernmost part of Japan. This study aimed to clarify the pathogenesis of this malignancy in this area by carrying out analysis of the histology and the Epstein-Barr (EBV) and human papillomavirus (HPV) infection. In the Department of Oral Surgery, Ryukyu University Hospital Okinawa, 188 cases of oral malignant tumours were encountered from 1996 to 2000. The histopathological examination and the sequence analysis of LMP-1 carboxy terminal region and EBNA2 region of EBV were carried out, as were the analysis of virus subtypes, A and B, BamHI-F and f, and C and D. Additionally, HPV infection in the squamous cell carcinomas were demonstrated using E6 and E7 region primer sets by PCR method. In Okinawa, 94% (177/188) of the cases were squamous cell carcinomas. A surprisingly large number of EBV (72%) and HPV (78%) infections in the oral squamous cell carcinomas were demonstrated. EBV type B virus infection was found in 36% of EBV-related oral squamous cell carcinoma in Okinawa, but in only 2-5% of the mainland cases. In both regions the incidence of the BamHI- f variant infection was very low. The infected virus in 79 out of 80 (39 Okinawan and 41 mainland) cases was BamHI- F type. In Okinawa, the numbers of C and D variants were almost equal, whereas in the mainland the D variant was rare. Further, a 30 bp deletion in LMP-1 gene was frequently demonstrated in Okinawan and mainland cases of type A virus, but not in type B virus. Lastly, single nucleotide mutations in EBNA2 region of type A virus when compared with B95-8 strain were demonstrated in Okinawan cases. The prognosis for (mostly EBV/HPV infected) squamous cell carcinomas in Okinawa was better than that in the mainland where most cases were negative for EBV and/or HPV.

Adult↗
PubMed1993

Nucleotide sequence of tobamovirus Ob which can spread systemically in N gene tobacco.

The genomic RNA sequence of tobamovirus Ob (Ob), which can spread systemically in tobacco carrying the N gene, was determined. It consists of 6507 nucleotides and contains four open reading frames, exactly corresponding to the genomic organization of tobamoviruses known so far, i.e. encoding the 130K, 180K, 30K and coat proteins. There were no nucleotide overlaps between any open reading frames. The Ob nucleic acid sequence, predicted protein sequences and gene organization were compared with those of other tobamoviruses reported previously. This virus was originally reported as a tomato mosaic virus; however, the nucleotide sequence data given here refute this classification. The determinants that allow tobamovirus Ob to overcome the N gene, a feature peculiar to this virus, were not identified apart from sequence data. This virus should be regarded as a new tobamovirus. The determinants interacting with the tentative N gene product have not yet been analysed.

Amino Acid Sequence↗
PubMed1994

Classification of Acinetobacter phages.

Eight phage species and type viruses are proposed. They belong to the Myoviridae, Siphoviridae, and Podoviridae families of tailed phages and are characterized by a combination of morphological and physicochemical properties. An unusual siphovirus species has an elongated head and transverse tail disks.

Acinetobacter↗
PubMedDate not supplied

Quality of life as a function of HIV classification.

The purpose of this research was to identify variables related to life quality for persons with Human Immunodeficiency Virus Infection and to ascertain if life quality differs according to the classifications of a positive serologic test for HIV antibodies (HIV+), AIDS-related complex (ARC), and Acquired Immunodeficiency Syndrome (AIDS). A convenience sampling technique was used to obtain subjects from AIDS support groups and affiliated agencies in a major southwest urban area. Ninety-five HIV-infected subjects completed a demographic data sheet, the Sickness Impact Profile (SIP), and the Symptom Distress Scale (SDS). The majority of subjects (59%) listed AIDS as their category of diagnosis, 25% were HIV+ only and 16% identified ARC as their disease classification. Subjects had SIP and SDS scores which indicated HIV-infection significantly affected their quality of life. Multivariate results indicated that quality of life indicators varied as a function of HIV classification. HIV-infection had the greatest disruption in psychosocial aspects of life. The impact of HIV-infection (both physical and psychosocial) was greatest in subjects with ARC and least among subjects who were HIV+ only.

AIDS-Related Complex↗
PubMed1990

The nucleotide sequences of the 3'-terminal regions of papaya ringspot virus strains W and P.

The sequences of cDNA clones encoding most of the NIb protein, the coat protein and the 3' untranslated region of papaya ringspot virus (PRV) strains W and P have been determined. The open reading frame of P strain PRV was confirmed by amino acid analysis. Nucleotide sequence comparisons of these strains show that they share a 98.2% identity in their NIb gene regions and a 97.7% identity in their coat protein genes. The sequences of these two strains are distinct from other potyvirus types, confirming their classification as two strains of the same virus. The NIb amino acid sequence possesses conserved amino acids characteristic of RNA-dependent RNA polymerases. Comparison of the coat protein amino acid sequence with those of other potyviruses shows perfectly conserved amino acids which may have functional significance.

Amino Acid Sequence↗
PubMed2006

Development and application of reference antisera against 15 hemagglutinin subtypes of influenza virus by DNA vaccination of chickens.

Reference antisera were produced against 15 influenza hemagglutinin (HA) subtypes using DNA vaccination to produce a high-quality polyclonal serum to the HA protein without antibodies to other influenza viral proteins. The HA gene from each of 15 different HA subtypes of influenza virus was cloned into a eukaryotic expression vector and injected intramuscularly, together with a cationic lipid, into 3- to 4-week-old specific-pathogen-free chickens. Birds were boostered twice at 4-week intervals after the initial injection, and in general, antibody titers increased after each boost. The antisera were successfully applied in the hemagglutination inhibition test, which is the standard method for the classification of the HA subtypes of influenza virus. We also demonstrated the HA specificity of the antisera by Western blot and immunodot blot analysis. DNA vaccination also provides a safer alternative for the production of HA-specific antibodies, since it is produced without the use of live virus.

Animals↗
PubMed1998

[Epstein-Barr virus infection in the pathogenesis of nasopharyngeal carcinoma].

Nasopharyngeal carcinomas (NPC) belong to the most frequent malignant tumours in certain parts of the world, e.g., south-east Asia, while they occur infrequently in western Europe. The association of NPCs with Epstein-Barr virus (EBV), a transforming human herpes virus, is well established. The current WHO classification recognises two major NPC histotypes, non-keratinising NPC and squamous cell NPC. EBV is invariably present in non-keratinising NPCs and the viral oncoprotein LMP-1 (latent membrane protein-1) is expressed in some cases. The tumour cells of non-keratinising NPCs show phenotypic features which are inducible by LMP-1 in vitro. These may contribute to the development of the lymphoid stroma which is characteristic of this tumour type. Furthermore, the virus is detectable in nasopharyngeal carcinoma in situ. Thus, the virus is likely to be involved in the pathogenesis of non-keratinising NPCs. By contrast, the association of squamous cell NPCs with EBV displays a geographical variability. It appears, therefore, that squamous cell NPCs are a heterogenous group of tumours distinct from non-keratinising NPCs.

Carcinoma↗
PubMed1992

Modifications of the 5' untranslated region of foot-and-mouth disease virus after prolonged persistence in cell culture.

The nucleotide sequence of the 5'-untranslated region (5'UTR) of the genome of foot-and-mouth disease virus (FMDV) R100, rescued after 100 passages of persistently infected BHK-21 cells, has been compared with that of the parental FMDV C-S8c1. The nucleotide sequence divergence between the two viruses in heteropolymeric regions is 1%. The few mutations located at the 5'-most terminal region (S fragment) and at the internal ribosome entry site (IRES) do not appear to affect significantly the tight secondary structure predicted for these RNA segments. Comparison of the 5'UTR of C-S8c1 or R100 RNA with that of other FMDV serotypes and subtypes indicates the presence of block deletions (or insertions) which do not correlate with the serological classification of FMDV. Remarkably, FMDV R100, a virus highly attenuated for mice and cattle, contains a polyribocytidylate (poly C) tract of about 420 nucleotides, 145 residues longer than its parental, virulent FMDV C-S8c1. This long poly C of R100 RNA includes a few uridine residues interspersed at fairly regular intervals. This is the longest highly homopolymeric tract described in a viral genome and, to our knowledge, in any informational biomolecule.

Animals↗
PubMed1992

[Identification and differentiation of the human herpes virus group using the PCR method].

Six kinds of human herpes viruses have been identified and classified on the basis of structure and characteristics. We studied the identification and classification of these types using PCR to amplify the virus-specific DNA sequences. This method showed higher sensitivity than the conventional method of virus isolation and culture for HSV and CMV detection. For each positive control, the viral DNA was amplified only when the complementary primers themselves were used. PCR apparently detects only the activated virus, because normal controls were negative when this method was used. Therefore, the present method is thought to closely reflect viral activation and infectious diseases in patients with latent infections.

Base Sequence↗