Chronic myelogenous leukemia in the monosomic cell line of a fertile turner syndrome mosaic (45,X/46,XX)

Malignancy in patients with constitutional chromosome abnormality is of interest not only because it permits insights into the relationship between chromosome abnormality and cancer, but also because it provides opportunities to address such questions as the clonality and evolution of tumors. We report Ph¹-positive chronic myelogenous leukemia (CML) in a 50-year-old mosaic (45,X/46,XX) Turner syndrome patient whose leukemia was restricted to the monosomic cell line. Our extensive cytogenetic studies of this patient demonstrated that non-leukemic normal cells persisted in the marrow and were able to proliferate during a period of temporary suppression of the leukemic clone following aggressive treatment.     

Point mutations in the P30 domain of the gag gene of Moloney murine leukemia virus

A series of point mutations in the P30 domain of the Moloney murine leukemia virus gag gene was generated by bisulfite treatment of heteroduplex DNAs containing a single-stranded region in the gag gene. One virus bearing such a mutation exhibited a coordinate defect in gag and pol function, and was similar to previously described deletion mutants with alterations in this gene. One mutant virus displayed a different phenotype: it could assemble virion particles and provide pol function, but the particles were defective in the early stages of infection. The continued concordance of the mutants' failure or ability to both assemble virions and provide pol lends further support to the proposal that similar parts of the gag gene are required for these two processes.     

Specificity of in vitro reconstitution of bromegrass mosaic virus

Bromegrass mosaic virus (BMV) RNA was allowed to compete with yeast tRNA or alfalfa mosaic virus (AMV) RNA for in vitro encapsidation by BMV protein. Various proportions of 32P-labeled foreign RNAs were added to a reassembly mixture (BMV protein: BMV RNA, 4:1) and the reassembly products were observed by analytical and rate-zonal sedimentation, and the RNA contents of the nucleocapsids were examined by gel electrophoresis. Incubation of BMV protein with tRNA alone produced 56 S particles containing five or six tRNA molecules per particle, but with both tRNA and BMV RNA present very little of the tRNA was incorporated. AMV 12 S RNA led to 64 S particles containing one AMV RNA molecule: with both AMV and BMV RNAs present, the smallest BMV RNA outcompeted the AMV RNA about fourfold, even though the two RNAs have similar molecular weights and biological functions. Evidently BMV protein does to some extent specifically recognise its own RNA molecules.     

Factors that affect genetic interaction during mixed infection with temperature-sensitive mutants of simian rotavirus SA11

A number of factors that affect genetic interaction during mixed infection with temperature-sensitive mutants of simian rotavirus SA11 have been examined. (1) Statistical analyses of recombination frequency (RF) indicated that (a) the variability noted in RF was not related to variations in experimental conditions and (b) a linear map of the mutations could not be drawn. (2) The wild phenotype of recombinant progeny was stable on passage. (3) Aggregates of progeny virus or heterozygous progeny virus particles did not contribute significantly to the observed RF. (4) RF increased in parallel with multiplicity of infection. (5) A maximal, or near maximal, RF was obtained at the earliest time significant recombinants could be detected. (6) Recombination was efficient at nonpermissive temperature. (7) Complementation did not occur or was inefficient. (8) Mutants from all recombination groups interfered with the growth of wild-type virus at both permissive and nonpermissive temperatures.     

The synthesis of coliphage T1 DNA: Requirement for host dna genes involved in elongation

Available Escherichia coli mutants with temperature-sensitive mutations in genes essential for DNA replication have been used to investigate the host protein involvement in the DNA synthesis of bacteriophage T1. This study has shown that T1 is independent of the E. coli initiation gene products dnaA, dnaC, dnaI, dnaP, and dnaT. The gene products of the polC, dnaG, and dnaZ loci, know to be involved in the elongation events of replication, are required for a productive T1 infection. T1 was found to be independent of the functioning of the dnaB gene product in the four dnaB mutants tested.     

Immunochemical characterization of mouse brain-associated theta (Thy-1) antigen.

The Thy-1 antigens or rat brain and thymus have been isolated and chemically characterized, but those of mice have not been identified. Moreover, it is uncertain whether the antigens are glycolipids or glycoproteins. This study with highly purified preparations of gangliosides GM₁, ¹GD_1a, GD_1b and GT_1b from bovine brain and several ganglioside fractions from mouse brain showed that Thy-1 activity does not reside in gangliosides, but rather in the chloroform-methanol-insoluble residue of brain remaining after extraction of gangliosides. The antigen could be solubilized from this residue with a non-ionic detergent. The antigenic activity of the solubilized preparation was heat-labile but resistant to periodate. The chemical properties of the Thy-1 antigen of mouse brain are discussed.     

Evaluation of activities in the health services

For planning or co-ordinating health services it is necessary to have reference points for evaluating similar departments in which homogeneous or equivalent activities are carried out. It is also necessary to consider the cost/benefit of the services. The paper presents several new indices of performance which may be applied to this problem and which enable quantitative comparisons to be made between hospitals and between departments. These indices include assessment of electrical hazards and service ability of equipment as well as the ratio of technical support staff to inpatient stay. The indices have been evaluated in a few large hospitals and found to be an effective management tool.     

Analysis and gene assignment of mRNAs of a paramyxovirus, simian virus 5

Polypeptides synthesized by the paramyxovirus SV5 in infected CV-1 cells were readily identified when the host cell was treated with actinomycin D. The unglycosylated forms of HN and Fo synthesized in infected cells in the presence of tunicamycin and HN and Fo synthesized in vitro were identified by immunoprecipitation with specific antibodies. Separation of SV5-specific poly(A)-containing RNAs on methyl-mercury agarose gels and in vitro translation of fractions, indicated that the viral polypeptides were translated from individual mRNAs except P (Mr approximately 44K) and the nonstructural polypeptide V (Mr approximately 24K) for which the mRNAs could not be separated. cDNA copies of SV5-specific mRNAs were synthesized and cloned in plasmid pBR322. Clones to NP, P + V, M, F, and HN were identified by hybrid-arrest and hybrid-selection translation of SV5 mRNAs. Tryptic peptide mapping of polypeptides P and V indicated that the peptides of V were a subset of those of P. Hybridization of cDNA probes to infected cell mRNAs separated on agarose gels permitted identification of the NP, P + V, M, F, and HN mRNAs and presumptive polycistronic mRNAs. The sizes and sequence homologies of these polycistronic mRNAs were used to derive a likely gene order on the SV5 50 S genome RNA.     

Coding assignments of Drosophila X virus genome segments: in vitro translation of native and denatured virion dsRNA

Both dsRNA genome segments of Drosophila X virus (DXV) were denatured and translated in vitro using nuclease-treated rabbit reticulocyte lysates. The synthesis of all four primary gene products was detected by polyacrylamide gel electrophoresis and autoradiography. Genome segment A (mol wt 2.3 X 10(6)) encoded polypeptides with molecular weights of 67,000 (67K), 34K, and 27K, whereas segment B (mol wt 22 X 10(6)) encoded the 110K polypeptide. The proteolytic processing of 67K which generates a 49K polypeptide in infected cells was also observed in vitro. Pulse-chase experiments indicated that synthesis of the three polypeptides encoded by genome segment A initiated independently and simultaneously, suggesting that segment A is polycistronic. Native (undenatured) DXV dsRNA could also be translated with high fidelity (vitro). The messenger activity of native dsRNA was abolished by S1 nuclease treatment but completely restored on subsequent denaturation. In vitro "pulse-chase" experiments using native dsRNA as messenger, indicated that the order of translation of polypeptides on genome segment A was 5'-67K-27K-34K-3'.