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Biomedical subjects

E Hunter

Publications and source records attributed to E Hunter.

At least 181 records · Page 10Linked to original sources
PubMed1979

Avian reticuloendotheliosis viruses: evolutionary linkage with mammalian type C retroviruses.

Reticuloendotheliosis viruses have been shown to be causative of tumors in a variety of avian species. The major structural protein of these non-genetically transmitted viruses is demonstrated to possess antigenic determinants common to those of all known mammalian type C viruses. These findings establish a mammalian origin for this oncogenic avian retrovirus group. None of the known mammalian type C virus groups demonstrated a closer immunological relationship to avian reticuloendotheliosis viruses. These results suggest that reticuloendotheliosis viruses have been non-genetically transmitted for a long period of evolution or that these viruses may have arisen by relatively recent infection of birds with an as yet undiscovered mammalian type C retrovirus.

Antigens, Viral↗
PubMed1979

Inhibition of Rous sarcoma virus replication by 2-deoxyglucose and tunicamycin: identification of an unglycosylated env gene product.

Two inhibitors of glycosylation, 2-deoxyglucose and tunicamycin, depressed the synthesis of infectious Rous sarcoma virus greater than 100-fold. Under the same conditions only a two- to threefold decrease in the production of virus particles was observed. The noninfectious particles had a lower density (1.145 g/ml) in isopycnic sucrose gradients and lacked the two virion glycoproteins, gp85 and gp37, found on infectious virions. The four internal structural proteins of the virus, p27, p19, p15, and p12, appeared to be assembled normally into the noninfectious virus. Polypeptides related to the Rous sarcoma virus glycoproteins were immunoprecipitated from pulse-labeled Rous sarcoma virus (Prague strain, subgroup B)-transformed cells. pr95gp, the polyprotein precursor to gp85 and gp37, was the major protein precipitated from untreated cells. PR95GP, THE POLYPROTEIN PRECURSOR TO GP85 AND GP37, WAS THE MAJOR PROTEIN PRECIPITATED FROM UNTREATED CELLS. This was absent in both tunicamycin- and 2-deoxyglucose-treatec ells, and a new polypeptide of molecular weight 57,000 to 58,000 was the major species precipitated. In tunicamycin-treated cells this product was unstable and was degraded during a 2-h chase; in 2-deoxyglucose-treated cells, on the other hand, the polypeptide appeared to be more stable and underwent partial glycosylation. The synthesis and processing of pr76, the polyprotein precursor to the internal structural proteins of the virion, occurred normally in both treated and untreated cells. It is concluded that the unglycosylated env gene product is a polypeptide of molecular weight 57,000 to 58,000.

Avian Sarcoma Viruses↗
PubMed1978

Amino-terminal amino acid sequence of the major structural polypeptides of avian retroviruses: sequence homology between reticuloendotheliosis virus p30 and p30s of mammalian retroviruses.

The major structural polypeptides, p30 of reticuloendotheliosis virus (REV) (strain T) and p27 of avian sarcoma virus B77, have been compared with regard to amino acid composition. NH2-terminal amino acid sequence, and immunological crossreactions. The amino acid composition of the two polypeptides is distinct, and a comparison of the first 30 NH2-terminal amino acids of REV p30 with that for the first 25 of B77 p27 yields only three homologous residues. In competition radioimmunoassays the polypeptides show no crossreactivity. A comparison of the amino acid composition and NH2-terminal amino acid sequence of REV p30 with those reported for several mammalian retrovirus p30s shows remarkable similarities. Both REV and mammalian p30s contain a large number of polar residues in their amino acid composition and show approximately 40% homology in the first 30 NH2-terminal amino acids. No crossreactivity could be observed, however, in competition radioimmunoassays between Rauscher murine leukemia virus p30 and that of REV. The observations reported here suggest a close evolutionary relationship between REV and the mammalian retroviruses.

Amino Acid Sequence↗
PubMed1976

An individual with Hb-Lepore-Baltimore- delta beta-thalassaemia in a Yugoslavian family.

The clinical, haematological and biochemical findings in a person with delta beta-thalassaemia and Hb-Lepore are described. The patient was a 24-year-old student who suffered from anaemia of intermediate severity with late onset of the clinical manifestations, had minor bone and facial deformities, but had no necessity for regular transfusions. Haemoglobins A and A2 were absent in this individual, and the Hb-Lepore has been identified as Lepore-Baltimore. Heterogeneity of gamma chain of the Hb-F follows the expected pattern. The study provides further evidence that neither beta nor delta chains are synthesized in cis to delta beta-thalassaemia or Hb-Lepore.

Adult↗
PubMed1975

Hemoglobin-Strumica or alpha 2 112(G19) His replaced by Arg beta 2. (With an addendum: hemoglobin-J-Paris-I, alpha 2 12(A10) Ala replaced by Asp beta 2, in the same population).

Hemoglobin-Strumica has been observed in five members of a Macedonian family. Histidyl residue in position 112 of the alpha chain of this variant is replaced by an arginyl residue. Two other variants (hemoglobin-Dakar and hemoglobin-Hopkins-2) in which this histidyl residue has been replaced by a glutaminyl and by an aspartyl residue, respectively, have been described (Rosa et al. (1968) 12 thCongr. Int. Soc. Haematol. New York, abstract, p. 73 and Charache, S. and Osterag, W. (1970) Bloodt 36, 852). The hemoglobin-Strumica heterozygotes have minimal hematological changes although this may not necessarily be associated with the hemoglobinopathy. Subjects heterozygous for hemoglobin-Dakar have a mild hemolytic anemia and hemoglobin-Hopkins-2 heterozygotes exhibit minimal hematological changes.

Adolescent↗
PubMed1975

Hemoglobin Fort Gordon or alpha2beta2145 Tyr replaced by Asp, a new high-oxygen-affinity hemoglobin variant.

Hemoglobin Fort Gordon, alpha2beta2145 Tyr replaced by Asp (HC2), has been observed in a 20-year-old black male with compensatory erythrocytosis. The variant was readily identified by electrophoresis and chromatography, and comprised about 30% of the red cell hemoglobin. The substitution was identified through analyses of tryptic peptides of various digests of the isolated beta chain. The oxygen affinity of whole blood was increased; two components were observed one of which had a greatly increased affinity for oxygen and a markedly reduced subunit cooperativity. It appears that the Tyr replaced by Asp substitution resembles the Tyr replaced by His substitution in hemoglobin Bethesda (Bunn, H. F. et al. (1972) J. Clin. Invest. 51, 2299-2309; Olson, J. S. and Gibson, G. H. (1972) J Biol. Chem. 247, 3662-3670; Adamson et al. (1972) J. Clin. Invest. 51, 2883-2888) in that both inhibit the quarternary change of the oxy to the deoxy conformation, resulting in greatly altered functional properties. Studies of a few members of the family were negative.

Adult↗
PubMed1975

Detection and quantitation of tetanus antitoxin in blood donations.

Passive haemagglutination and IEOP have been used both to detect and to measure tetanus antitoxin in human donor sera. Forty percent of blood donors had detectable antitoxin but only 9% had levels suitable for production of human antitetanus immuoglobulin (larger than or equal to 2 IU/ml). The incidence of high titre antitoxin was significantly greater in men and was unrelated to the ABO blood group system. The prevalence of antitoxin in selected donor groups and immunized staff is shown.

ABO Blood-Group System↗