Purification and polypeptide composition of Semliki Forest virus RNA polymerase

A purification method for Semliki Forest virus-specified RNA-dependent RNA polymerase from BHK cells is described. The procedure entails (i) the preparation of a crude cell lysate by Dounce homogenization of cells 3-5 h post-infection, (ii) differential centrifugation to give a 15 000 g 'mitochondrial' pellet, (iii) equilibrium centrifugation on discontinuous sucrose gradients (Friedman et al. 1972) to give a membranous band of density 1-16 g/ml, (iv) solubilization with Triton N-101 and velocity centrifugation to give a 25S solubilized polymerase complex and (v) affinity chromatography through an oligo (dT)-cellulose matrix bearing immobilized 42S virus particle RNA. The overall purification was approx. 360-fold with a 5% recovery of activity. Of the various intermediate fractions in the purfication procedure, only the relatively crude post-nuclear supernatant fraction was competent to synthesize the major single-stranded RNAs found in infected cells. Other fractions incorporated precursor only into replicative intermediate (RI) or replicative from (RF). Analysis of the product RF showed that it was of the same size and could bind to the same extent to oligo (dT)-cellulose as the RF isolated directly from lysates of infected cells. Displacement hybridization and ribonuclease digestion suggested that the purified polymerase could only complete previously initiated progeny positive strands using negative strands as template and, even in its most highly purified form, was still tightly bound to its template. Analysis on polyacrylamide slab gels revealed the presence of three 35S-labelled polypeptides in the purified polymerase preparation, but a polypeptide which had identical electrophoretic mobility to the lowest mol. wt. polypeptide of the purified polymerase was also present in material from mock-fected cells which had been taken through the purification procedure. From these results we conclude that only two virus-specified polypeptides are present in the polymerase. A scheme for the synthesis of these polypeptides is presented in the accompanying paper.     

Neurological aspects of rubella virus infection

Rubella virus is a single-stranded, plus-sense RNA virus belonging to the Togaviridae family. Rubella virus infection causes a benign disease known as rubella or German measles, however infection during early pregnancy can lead to severe birth defects known as congenital rubella syndrome (CRS). Sequelae of rubella virus infection include three distinct neurological syndromes: a postinfectious encephalitis following acute infection, a spectrum of neurological manifestations following congenital infection, and an extremely rare neurodegenerative disorder, progressive rubella panencephalitis (PRP), that can follow either congenital or postnatal infection. The pathogenesis of all three of these syndromes is incompletely understood. Virus invasion and replication in the brain has only been definitively demonstrated in CRS and appears to account for the majority of neurological lesions observed in this disease. Immune-mediated pathology is particularly evident in PRP and may be autoimmune in nature, possibly triggered by molecular mimicry between viral and host epitopes, considering the apparent lack of virus in the brain. The pathogenesis of rubella encephalitis following acute infection has not been determined.     

Phospholipid and cholesterol composition of rubella virus and its host cell BHK 21 grown in suspension cultures

In the treatment of acute leukoses, from the first onset of the disease till the occurrence of the first remission, as well as in the course of intesive hemiotherapy, the substitution therapy by blood derivatives has the great importance. Anaemia, granulocytopenia, hypoproteinaemia and hemorrhagic syndroms, caused by thrombocytopenia, liver diseases and disseminated intravascular coagulation, are the most frequent disorders requiring the substitution therapy. Authors presented the advantages of the substitution therapy by blood derivatives upon the whole blood.     

Infantile achalasia. Brief clinical report

Achalasia of the esophagus is an unusual lesion in childhood and is quite rare under the age of one year. The case of a 3-month-old child with esophageal achalasia treated with a Heller esophagomyotomy is illustrated. Seven previously documented cases of achalasia in children under the age of one year are reviewed and the difficulties of diagnosing this lesion in childhood are discussed.     

Hepatic emboli following inferior vena caval ligation. Brief report

Radionuclide venography performed by foot vein injection of 99mTc MAA and 99mTc DTPA in a 34-year-old man approximately one year after inferior vena caval ligation demonstrated an unusual collateral pathway between the veins of the lower extremities and the portal vein, and also evidence for multiple hepatic emboli. This is a newly recognized sequela of inferior vena caval ligation.     

Evaluation of Wistar RA27/3 rubella virus vaccine in children

Because the Wistar RA27/3 strain rubella virus vaccine has potentially important advantages over rubella vaccines currently licensed in the United States, a field trial was conducted in Minnesota and Wisconsin in 1974 to evaluate RA27/3 in this country. Two hundred eighty-five (99.7%) of 286 susceptible children given RA27/3 subcutaneously seroconverted, with a geometric mean hemagglutination inhibition (HI) titer of 81.2. Twenty-eight (23%) of 122 children with rubella antibodies before immunization had fourfold or greater rises in rubella HI titers. The highest percentage of booster responses occurred in children with low preimmunization titers. Side effects were reported in 34% of subjects, but only one reaction associated with RA27/3 was serious: in a 5-year-old boy, arthritis of the left hip developed 31 days after immunization. This study indicates that RA27/3 vaccine produced a very high rate of seroconversion with high postimmunization HI titers. The ability to elicit significant booster responses in children with low levels of HI antibodies suggests that RA27/3 could be used to boost immunity in women of childbearing age whose rubella titers have declined to undetectable levels.     

Arthritis related to rubella: a complication of natural rubella and rubella immunization

The success of the childhood rubella immunization program has caused an upward shift in age of those susceptible to rubella. An associated increase has taken place in the incidence of rubella-related arthritis, which occurs more often in the post-pubertal population. Fortunately, however, the arthralgia-arthritis syndromes of naturally acquired rubella and those associated with vaccination are usually transient and mild.     

Brief report. Social self-concept of educated employed and educated unemployed women

A prospective cohort study on 1103 consecutive patients undergoing general surgery with a follow-up of up to 30 days was undertaken to analyse the risk factors for surgical-site infection (SSI). Relative risks (RRs), crude and multiple-risk factors adjusted for by logistic regression analysis, and their 95% confidence intervals were calculated. One hundred and four patients (9.4%) developed infection, 81 in hospital and 23 at home. Predictors for in-hospital SSI differed from those for post-discharge SSI. In a crude analysis, an increased risk of post-discharge SSI occurred after clean-contaminated surgery (but not contaminated surgery). Stepwise logistic regression failed to identify any significant predictor for post-discharge SSI.     

Immunotherapy of cancer with "immune" RNA. A preliminary report

A phase I clinical trial of immunotherapy with "Immune" RNA was undertaken fifteen months ago. Twenty-six cancer patients were treated with RNA extracted from the lymphoid organs of sheep immunized with either autologous tumor cells or allogeneic tumor cells of the same histologic type. Eighteen patients had gross disease and eight had minimum residual disease. RNA was administered weekly, intradermally, at doses up to 9 mg/week without any significant local or systemic toxicity. Four patients improved, thirteen achieved stability of disease or possible improvement, seven were treatment failures, and two are indeterminate. Lymphocyte-mediated cytotoxicity to allogeneic tumor target cells of the same histologic type were monitored in eleven patients. In seven patients, cytotoxicity increased after "Immune" RNA therapy; no change was observed in three patients; a decrease was noted in one patient. There appeared to be a possible correlation between cytotoxicity assessed in vitro and clinical response. There is some evidence that these responses may be specific for the particular tumor used to immunize the RNA donor.     

Detection of astroviruses in feces of a cat with diarrhea. Brief report

Astroviruses were detected by electron microscopy in the feces from a 4 month old kitten with diarrhea. The mean diameter of the viral particles was 28.7 nm, and they showed characteristic five- or six-pointed star-shaped surface configurations. The clinical disease manifested by the cat and the observed morphology of the viral particles are consistent with previous reports on astroviruses of other species.     

Automatic detection of conserved RNA structure elements in complete RNA virus genomes

We propose a new method for detecting conserved RNA secondary structures in a family of related RNA sequences. Our method is based on a combination of thermodynamic structure prediction and phylogenetic comparison. In contrast to purely phylogenetic methods, our algorithm can be used for small data sets of approximately 10 sequences, efficiently exploiting the information contained in the sequence variability. The procedure constructs a prediction only for those parts of sequences that are consistent with a single conserved structure. Our implementation produces reasonable consensus structures without user interference. As an example we have analysed the complete HIV-1 and hepatitis C virus (HCV) genomes as well as the small segment of hantavirus. Our method confirms the known structures in HIV-1 and predicts previously unknown conserved RNA secondary structures in HCV.