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Biomedical subjects

C W Anderson

Publications and source records attributed to C W Anderson.

At least 145 records · Page 8Linked to original sources

Identification of the initiation site of poliovirus polyprotein synthesis.

The complete nucleotide sequence of poliovirus RNA has a long open reading frame capable of encoding the precursor polyprotein NCVP00. The first AUG codon in this reading frame is located 743 nucleotides from the 5' end of the RNA and is preceded by eight AUG codons in all three reading frames. Because all proteins that map at the amino terminus of the polyprotein (P1-1a, VP0, and VP4) are blocked at their amino termini and previous studies of ribosome binding have been inconclusive, direct identification of the initiation site of protein synthesis was difficult. We separated and identified all of the tryptic peptides of capsid protein VP4 and correlated these peptides with the amino acid sequence predicted to follow the AUG codon at nucleotide 743. Our data indicate that VP4 begins with a blocked glycine that is encoded immediately after the AUG codon at nucleotide 743. An S1 nuclease analysis of poliovirus mRNA failed to reveal a splice in the 5' region. We concluded that synthesis of the poliovirus polyprotein is initiated at nucleotide 743, the first AUG codon in the long open reading frame.

Amino Acid Sequence↗

Predictability of the distressed term infant.

The delivery of a distressed term infant is infrequent but often requires intensive therapy. This study investigates the primary causes for such distress and the period (antepartum intrapartum, neonatal) when each complication was initially recognized. During a 1-year period, 168 term infants (8% of 2,057 term deliveries) required admission to the newborn intensive care unit. The primary disorders were similar to those of 228 infants transported from community hospitals and involved suspected sepsis, metabolic problems, major anomalies, birth asphyxia, and respiratory distress. Only one third (59 cases, 35%) of the subsequently distressed infants was anticipated during the antepartum period. The term infant who requires more than routine nursery care cannot necessarily be predicted until labor or delivery.

Female↗

Primary structure, gene organization and polypeptide expression of poliovirus RNA.

The primary structure of the poliovirus genome has been determined. The RNA molecule is 7,433 nucleotides long, polyadenylated at the 3' terminus, and covalently linked to a small protein (VPg) at the 5' terminus. An open reading frame of 2,207 consecutive triplets spans over 89% of the nucleotide sequence and codes for the viral polyprotein NCVPOO. Twelve viral polypeptides have been mapped by amino acid sequence analysis and were found to be proteolytic cleavage products of the polyprotein, cleavages occurring predominantly at Gln-Gly pairs.

Amino Acid Sequence↗

Poliovirus replication proteins: RNA sequence encoding P3-1b and the sites of proteolytic processing.

A partial amino-terminal amino acid sequence of each of the major proteins encoded by the replicase region (P3) of the poliovirus genome has been determined. A comparison of this sequence information with the amino acid sequence predicted from the RNA sequence that has been determined for the 3' region of the poliovirus genome has allowed us to locate precisely the proteolytic cleavage sites at which the initial polyprotein is processed to create the poliovirus products P3-1b (NCVP1b), P3-2 (NCVP2), P3-4b (NCVP4b), and P3-7c (NCVP7c). For each of these products, as well as for the small genome-linked protein VPg, proteolytic cleavage occurs between a glutamine and a glycine residue to create the amino terminus of each protein. This result suggests that a single proteinase may be responsible for all of these cleavages. The sequence data also allow the precise positioning of the genome-linked protein VPg within the precursor P3-1b just proximal to the amino terminus of polypeptide P3-2.

Amino Acid Sequence↗

Adenovirus type 2 expresses fiber in monkey-human hybrids and reconstructed cells.

Adenovirus type 2 protein expression was measured by indirect immunofluorescence in monkey-human hybrids and in cells reconstructed from monkey and human cell karyoplasts and cytoplasts. Monkey-human hybrid clones infected with adenovirus type 2 expressed fiber protein, whereas infected monkey cells alone did not. Hybrids constructed after the parental monkey cells were infected with adenovirus type 2 demonstrated that fiber synthesis in these cells could be rescued by fusion to uninfected human cells. Thus, human cells contain a dominant factor that acts in trans and overcomes the inability of monkey cells to synthesize fiber. Cells reconstructed from infected human karyoplasts and monkey cytoplasts expressed fiber, whereas cells reconstructed from infected monkey karyoplasts and human cytoplasts did not. These results are consistent with the hypothesis that the block to adenovirus replication in monkey cells involves a nuclear event that prevents the formation of functional mRNA for some late viral proteins including fiber polypeptide. Furthermore, they suggest that the translational apparatus of monkey cells is competent to translate functional fiber mRNA synthesized in human cells.

Adenoviruses, Human↗

Synchronous tuberculous involvement of both ears and the larynx in a patient with active pulmonary disease.

Since the incidence of pulmonary tuberculosis in the United States has declined dramatically, this diagnosis is often overlooked in the differential diagnosis of puzzling extra-pulmonary disease. Recent publications emphasize that tuberculosis still needs to be considered in patients with chronic ear, nose, and throat complaints. A patient with tuberculosis involving both middle ears, the larynx, and the lung was correctly diagnosed only after a prolonged delay and several visits for chronically draining ears. As a result of the infection, subtotal bilateral tympanic membrane perforations and a profound hearing loss in both ears occurred. This case emphasized the importance of a high index of suspicion in the evaluation and treatment of patients with symptoms of chronic diseases who fail to respond to conventional therapy.

Aged↗

Changes in amniotic fluid optical density at 450 millimicron in Rh-sensitized patients after maternal hydrocortisone treatment.

In anticipation of elective premature delivery (32 to 34 weeks of gestation), five Rh-sensitized pregnant women were given hydrocortisone succinate for enhancement of fetal lung maturation. Serial amniocenteses were performed and an abrupt drop in the optical density at 450 millimicron (OD450) was observed in all cases immediately after administration of the steroid. Two infants in whom the OD450 remained low were followed safely to term. The others were delivered prematurely. All infants were Rh-sensitized and required one or more exchange transfusions, and all survived. It is tempting to speculate that glucocorticoids alter the antigen-antibody affinity and inhibit splenic macrophage sequestration, thus reducing erythrocyte destruction. Maternal steroid administration may prove to be therapeutic in the management of Rh-sensitization, but until its mechanisms are further delineated, extreme caution must be used in the interpretation of OD450 changes.

Amniotic Fluid↗

Synthesis of gamma-L-glutaminyl-[3,5-3H]4-hydroxybenzene and the study of reactions catalyzed by the tyrosinase of Agaricus bisporus.

gamma-L-Glutaminyl-[3,5-3H]4-hydroxybenzene was synthesized in order to study the kinetics of its hydroxylation by tyrosinase purified from Agaricus bisporus and to explore its role in the induction of the dormant state in the spores of this species. It was found to be unique among the monophenolic substrates for tyrosinase in that the lag period for the hydroxylation reaction decreased with increasing substrate concentration. Unlike previously studied compounds, this phenol appeared to function as an electron donor, allowing it to act as its own co-substrate in the hydroxylation reaction. Its catechol product, gamma-L-glutaminyl-3,4-dihydroxybenzene, was found to be a superior co-substrate, yielding its electrons more readily (oxidation peak potential +0.18 V as compared with +0.65 V for the phenol). In situ periodate oxidation of gamma-L-glutaminyl-3,4-dihydroxybenzene to gamma-L-glutaminyl-3,4-benzoquinone confirmed the co-substrate role of the catechol in the hydroxylation reaction. The tyrosinase-mediated oxidation of gamma-L-glutaminyl-3,4-dihydroxybenzene to gamma-L-glutaminyl-3,4-benzoquinone occurred with an apparent Km = 1.54 mM and Vmax = 0.36 mmol/min/mg of enzyme. gamma-L-Glutaminyl-4-hydroxybenzene acted as an inhibitor of the oxidation reaction.

Agaricales↗

Immunoassay by differential pulse polarography.

An immunological method based on labeling an antigen with an electroactive group detectable by differential pulse polarography has been demonstrated. Estriol labeled with mercuric acetate is electroactive, giving a reduction wave at -300 millivolts versus a standard calomel electrode. Addition of estriol antibody to 4-mercuric acetate estriol diminishes the peak current as a result of the antigen-antibody binding reaction. Separation of free-labeled estriol from antibody-bound-labeled antigen is unnecessary. The method is potentially useful as an analytical immunological technique.

Estriol↗