Multiple aberrant substructures of T-even bacteriophage particles occurred when amino acid analogues or antimetabolites were present during phage growth. Certain aberrant substructures were induced by specific analogues or antimetabolites. In particular, it was observed by electron microscopy that l-canavanine, an arginine analogue, gave rise to polyheads; l-azetidine-2-carboxylic acid, a proline analogue, gave rise to polytail tubes; and 1,2,4-trizaole-3-alanine, a histidine analogue, proflavine, and actinomycin D all gave rise to small heads. These aberrant substructures were similar to those reported earlier with conditional lethal mutants (amber) of T4D in a restrictive host.
Dimethyl sulfoxide (DMSO) disrupted T-even bacteriophages as well as λ bacteriophage. The component substructures of T2L, T4B01, or T6, in particular heads, were readily isolated after treatment with 67% DMSO (v/v). In contrast, concentrations of DMSO above 50% not only separated heads from tails of bacteriophage λ but led to degradation of the λ heads. Examination of the isolated free heads of T-even bacteriophage indicated that a distinct neck substructure was attached to one apex of the head. On some free tails a similar neck substructure was also found at the proximal end of the sheath. The dimensions of this neck substructure were found to be about 130 by 180 A; by virtue of its size and morphological attachment to the free heads, it was concluded that this was a distinct substructure and not an extension of the tail tube.
T-even bacteriophages were grown and purified in bulk quantities. The protein coats were disrupted into their component substructures by treatment with 67% dimethyl sulfoxide (DMSO). Tail fibers and tubes were purified on glycerol-CsCl-D2O gradients and examined with respect to sedimentation properties, subunit molecular weights, amino acid composition, isoelectric points, and morphology. It was found that intact tail fibers had a sedimentation coefficient of 12 to 13S and that dissociated fibers consisted of three classes of proteins having molecular weights of 150 K ± 10, 42 K ± 4, and 28 K ± 3 daltons. A model was constructed in which the 150-K subunit folded back on itself twice to give a three-stranded rope. Each 150-K subunit then represented a half-fiber and it was proposed that the role of the 42- and 28-K subunits was to hold each half-fiber together as well as serve as a possible link with other substructures. Isoelectric point studies also indicated that there were three different proteins with pI values of 3.5, 5.7, and 8.0. Amino acid analyses indicated that fibers had a composition distinct from other phage substructures. In addition, a striking difference was noted in the content of tryptophan among the phages examined. T4B had three to five times more tryptophan than did T2L...
Tail plates obtained from T4D amber mutants were examined with respect to sedimentation behavior, subunit molecular weights, amino acid composition, isoelectric points, and morphology. Intact plates had an S20,w of 77S from pH 5 to 9. The only conformational change noted was that below pH 5 tail plates readily dimerized yielding vis-à-vis dimers with an S20,w of 124S. Dissociated plates consisted of three major proteins with molecular weights of 53 K ± 5, 31 K ± 3, and 17 K ± 2 daltons. The amino acid analyses indicated that plates had a composition distinct from fibers and tubes and were relatively rich in tryptophan. Degradation studies with dimethyl sulfoxide (DMSO) indicated that tail plates had a unique biological structure. After treatment with DMSO, and to some extent without DMSO, or from lysates of defective mutants, tetrad structures were observed in the electron microscope. These structures had an amino acid content and relative amounts of types of subunits similar but not identical to intact plates. It was proposed that plates were composed of nine such tetrads giving rise to a structure with six- and threefold symmetry.
The cytokinin-active ribonucleosides present in tRNA from etiolated Phaseolus vulgaris L. seedlings have been isolated and identified as cis-ribosylzeatin, 2-methylthio-ribosylzeatin, and N6-(Δ2-isopentenyl)-adenosine. The structures of the compounds were established on the basis of their chromatographic properties and the mass spectra of their permethylated and perdeuteromethylated derivatives. Cis-ribosylzeatin was the major cytokinin-active constituent of tRNA from this source.
This study tested the reversal of subcellular remodelling in heart failure due to myocardial infarction (MI) upon treatment with losartan, an angiotensin II receptor antagonist. Twelve weeks after inducing MI, rats were treated with or without losartan (20 mg/kg; daily) for 8 weeks and assessed for cardiac function, cardiac remodelling, subcellular alterations and plasma catecholamines. Cardiac hypertrophy and lung congestion in 20 weeks MI-induced heart failure were associated with increases in plasma catecholamine levels. Haemodynamic examination revealed depressed cardiac function, whereas echocardiographic analysis showed impaired cardiac performance and marked increases in left ventricle wall thickness and chamber dilatation at 20 weeks of inducing MI. These changes in cardiac function, cardiac remodelling and plasma dopamine levels in heart failure were partially or fully reversed by losartan. Sarcoplasmic reticular (SR) Ca2+-pump activity and protein expression, protein and gene expression for phospholamban, as well as myofibrillar (MF) Ca2+-stimulated ATPase activity and α-myosin heavy chain mRNA levels were depressed, whereas β-myosin heavy chain expression was increased in failing hearts; these alterations were partially reversed by losartan. Although SR Ca2+-release activity and mRNA levels for SR Ca2+-pump were decreased in failing heart...
Don Chapman was a Silver Badger, a unique distinction given to the first class of Brock University students upon their graduation in 1967 and 1968. Mr. Chapman was an active participant in the student life during his years at Brock University. After graduation he continued to take an active role as a member of the alumni of Brock University. Mr. Chapman was a teacher at St. John’s-Kilmarnock School, Waterloo, Ont., until his death in 2005.; Fonds consists of printed and handwritten material. It also includes photographs of student participants in the Grape and Wine Festival parade and three dimensional items, including a graduation hood, a pennant, a gavel and bookends.
One way to understand the value of sporting ‘superstars’ is to examine the effect they have on match attendances and revenue. Arguably, the most famous sports star in Australia was Sir Donald Bradman, whose batting average has far exceeded that of any cricket players. This paper examines the value of Don Bradman by estimating an empirical model of the effect of Bradman on cricket match attendances for Ashes Test matches in Australia. The attendance effect – of over 7,000 additional people each day on which he batted – is then used to derive an estimate of the effect on revenue. We find that Bradman generated considerable additional revenue, though the range of the estimates is very large. The Australian Cricket Board, as the monopoly supplier of cricket, was able to obtain all the extra proceeds.; no
Disease related antigens are of great importance in the clinic. They are used as markers to screen patients for various forms of cancer, to monitor response to therapy, or to serve as therapeutic targets (Chapman et al., Ann Oncol 18(5):868–873, 2007; Soussi et al., Cancer Res 60:1777–1788, 2000; Anderson and LaBaer, J Proteome Res 4:1123–1133, 2005; Levenson, Biochim Biophy Acta 1770:847–856, 2007). In cancer endogenous levels of protein expression may be disrupted or proteins may be expressed in an aberrant fashion resulting in an immune response that bypasses self tolerance (Soussi et al., Cancer Res 60:1777–1788, 2000; Disis et al., J Clin Oncol 15(11):3363–3367, 1997; Molina et al., Breast Cancer Res Treat 51:109–119, 1998). Protein microarrays, which represent a large fraction of the human proteome, have been used to identify antigens in multiple diseases including cancer (Anderson and LaBaer, J Proteome Res 4:1123–1133, 2005; Disis et al., J Clin Oncol 15(11):3363–3367, 1997; Hudson et al., Proc Natl Acad Sci U S A 104(44):17494–17499, 2007; Beyer et al., J Neuroimmunol 242:26–32, 2012). Typically, arrays are probed with immunoglobulin (Ig) samples from patients as well as healthy controls, then compared to determine which antigens (Ag's) are more reactive within the patient group (Hudson et al....
Antibodies to dexamethasone 21-hemisuccinate conjugated to bovine serum albumin were produced in rabbits. Antisera diluted 1:3000 bound 50% of 90pg of [1,2-3H]dexamethasone. The cross-reaction of the antisera with other synthetic and natural corticosteroids was measured.
Donald A. Barr's Introduction to U.S. Health Policy: The Organization, Financing, and Delivery of Health Care in America (second edition, 2007) offers a lucid and informative overview of the U.S. health system and the dilemmas policy makers currently face. Barr has provided a balanced introduction to the way health care is organized, financed, and delivered in the United States. The thirteen chapters of the book are quite comprehensive in the topics they cover. Even those knowledgeable about the U.S. health care system are likely to find much to stimulate their thinking in the text. The book can also appropriately serve as a basic text for a health policy course or in the medical or nursing school curriculum.