Multiple reiteration of a 40-bp nucleotide sequence in the inverted terminal repeat of the genome of a canine adenovirus

The DNA of a vaccine strain of canine adenovirus type 1 [ICHV vaccine; Connaught Laboratories, Ltd.; CAV-1(CLL)] has been cloned in plasmid pAT153 in the form of subgenomic BamHI digestion fragments. Analysis of the nucleotide sequences of cloned terminal fragments has revealed an inverted terminal repeat (ITR) with a minimum length of 198 nucleotides, including a tandem reiteration of the 40-bp nucleotide sequence from positions 14 to 53. The ITRs had the 5'-CATCATCAAT ... sequence typical of adenoviruses and the highly conserved sequence ATAATATAC (nucleotides 9-17) of human strains. Additionally, one BamHI A clone (left terminus) contained three sequential copies of the 40-bp sequence, and two BamHI C clones (right terminus) contained at least seven. These did not appear to be artifacts of cloning, since evidence was obtained that the multiple reiterations also occurred in DNA isolated from intact virus. By analogy with human adenoviruses, the repetitive sequence in the CAV-1(CLL) genome encompasses the entire nuclear factor I (NFI) binding site of the origin of DNA replication. Additionally, the 40-bp nucleotide sequence was found to contain the sequence AGG(N)4GCCTAA (nucleotides 27-39), which closely resembles the concensus sequence of the human adenovirus NFI binding site [TGG(N)6-7GCCAA; nucleotides 25-38]. It appears, therefore, that the Connaught CAV-1 vaccine contains reiterated copies of an essential part of the adenoviral origin of DNA replication. A mechanism is proposed for the generation of multiple reiterations of sequences in the right ITR, given an initial single tandem repeat in the left ITR.

Accessibility and multivalency of immobilized Cibacron blue F3GA

The effect of immobilized dye concentration on protein complexation was observed using zonal chromatography. A monomeric protein, octopine dehydrogenase, was retained by a single interaction to a Sepharose CL-6B column containing 11.6 mM immobilized Cibacron blue F3GA. By contrast, a tetrameric protein, lactate dehydrogenase, was retained by the same column by multiple interactions. The degree of multiple interactions was found to systematically increase with increasing immobilized dye concentration. The concentration of immobilized dye accessible to protein was found to be inversely related to the concentration of ionic components in the solvent. Zonal chromatographic measurements of free dye and unconjugated matrix suggest that increasing the concentration of ionic components promotes the adsorption of immobilized dye to the adjacent matrix surface. Such adsorption markedly affects both the capacity of an immobilized dye column and the multiplicity of its interaction with oligomeric proteins.

Klebsiella pneumoniae liver abscess associated with septic endophthalmitis

Metastatic septic bacterial endophthalmitis is a rare, but devastating disease. We encountered seven cases of pyogenic liver abscess associated with septic endophthalmitis during a recent four-year period. The causative organism was a pure culture of Klebsiella pneumoniae. The diagnosis was made by results of a blood culture in seven of the cases, liver aspirate culture in four, and eye contents or conjunctival culture in four. Chest roentgenographic examination showed pulmonary embolization in four patients, purulent meningitis in one patient, and suspicious prostatic abscess in one patient. Despite diligent antibiotic therapy, six patients lost their vision and one had impaired vision. This poor outcome for septic endophthalmitis seems to result from delayed diagnosis and lack of scheduled periocular injections of antibiotics. A combination course of treatment by the internist and ophthalmologist acting aggressively, both diagnostically and therapeutically, is needed in the future. To have seven cases of K pneumoniae liver abscess complicated by septic endophthalmitis during a period of four years in one hospital is very unusual. To our knowledge, it has never been reported in the literature.

Zonal chromatographic analysis of the interaction of alcohol dehydrogenase with blue-sepharose

The interaction between horse liver alcohol dehydrogenase and Reactive blue 2 immobilized on Sepharose CL-6B was measured by zonal chromatography. Each protein molecule was retained by a single immobilized dye using a Blue-Sepharose column containing a total of 1.38 mM dye. However, the protein was predominantly retained by two immobilized dye molecules using a darker Blue-Sepharose column containing a total of 11.6 mM dye. The dissociation constant measured for the alcohol dehydrogenase--immobilized dye complex on each column is identical to the inhibition constant for the alcohol dehydrogenase--free Reactive blue 2 complex: 4.5 +/- 0.8 microM.

Nonmuscle tropomyosin from ascites tumor cell microvilli

Tropomyosin has been isolated from microvilli preparations from 13762 rat mammary adenocarcinoma ascites tumor cells by Triton extraction and pelleting of the microvillar microfilament core, extraction of the microfilament core with 1 M KCl, heat treatment, and hydroxyapatite chromatography. Three major isoforms, designated 31K-a (acidic), 31K-b (basic), and 29K, were identified as tropomyosins by two-dimensional isoelectric focusing-dodecyl sulfate electrophoresis, a urea shift on dodecyl sulfate electrophoresis, chemical cross-linking, amino acid analysis, and molecular weight determinations. The native (60,000) and subunit (31,000 and 29,000) molecular weights, the amino acid composition, and the stoichiometry for binding to F-actin (actin/tropomyosin, 6:1) were typical of nonmuscle tropomyosins. The amount of tropomyosin present in the microvilli preparations is sufficient to saturate about half of the microvillar F-actin. By two-dimensional isoelectric focusing-dodecyl sulfate electrophoresis, the 31K isoforms appeared similar to isoforms of normal rat kidney cells but the 29K isoform was apparently smaller than any normal rat kidney isoforms. All three isoforms bound to F-actin, but the 29K form bound most strongly. Its behavior was similar to that of muscle tropomyosin, exhibiting saturable binding as a function of both ionic strength and Mg2+ concentration. In contrast, the 31K isoforms bound more weakly and required higher concentrations of Mg2+ for binding than that required for saturation with 29K (4 mM). These results clearly indicate that nonmuscle tropomyosin isoforms from a single source and location (subplasmalemmal) in the cell can exhibit different properties.

China: traditional healing and contemporary medicine

This paper shows how the health professions must meet the demands posed by China's vast geographical area, her population problem, her increasing technological development and economic situation, by utilizing available health resources as well as manpower in order to fulfil 'the national guarantee--to serve the people'.

Quantitative analysis of protein: immobilized dye interaction

The interaction of rabbit muscle lactate dehydrogenase with reactive blue 2 immobilized on Sepharose CL-6B was quantitatively evaluated by analytical procedures using both frontal and zonal chromatography and also static equilibrium methodology. All three analytical procedures give a common result, namely (i) that each enzyme molecule is retained by a single immobilized dye molecule; (ii) that the immobilized dye binds to the protein at an NADH binding site with an affinity identical to that of the free dye; and (iii) that less than 2% of the immobilized dye is accessible to the enzyme. The very small fractional accessibility is not due to steric exclusion but likely is a result of adsorption of the immobilized dye to the matrix surface.

Shared idiotopes among monoclonal antibodies specific for A/PR/8/34 (H1N1) and X-31(H3N2) influenza viruses

A monoclonal antibody specific for the hemagglutinin (HA) of influenza A X-31 (H3N2) virus (X-31) was obtained during a fusion of spleen cells from a BALB/c mouse immunized with influenza A/PR/8/34 (H1N1) virus (PR8). This monoclonal antibody (Py206) shares crossreactive idiotopes expressed on several monoclonal antibodies specific for PR8 HA and X-31 HA as well as an individual idiotope shared with one monoclonal antibody specific for X-31 HA. The presence of shared idiotypy among antibodies of such diverse binding specificities may result from regulation by idiotype-specific T cells. In addition, the results suggest that, in contrast to the diversity of paratypes expressed, relatively few germ-line variable region genes may be used in the antibody response to influenza A virus antigens.