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Biomedical subjects

C L Harris

Publications and source records attributed to C L Harris.

At least 73 records · Page 4Linked to original sources
PubMed1977

Isoleucyl-tRNA synthetase inactivation and the extent of aminoacylation of tRNAIle from Escherichia coli.

A difference in isoleucine acceptance between normal and sulfur-deficient tRNA from Escherichia coli C6 (rel-, met-, cys-) was eliminated when more isoleucyl-tRNA synthetase was added at the reaction plateau. Enzymatic deacylation was similar for both tRNAs. These results suggest that enzyme inactivation caused a premature reaction plateau which was not predicted by the rates of acylation and deacylation.

Amino Acyl-tRNA Synthetases↗
PubMed1976

Permanent atrial paralysis.

A forty-four year old female presented with hemiparesis a slow supraventricular rhythm without "P" wave activity and was subsequently found to have atrial paralysis. On treadmill exercise testing the patient's heart rate increased to 118/min. It is felt that this most likely represents sinus rhythm with sinoventricular conduction and that the slow resting heart rate is secondary to a sick sinus node syndrome.

Acute Disease↗
PubMed1976

Increased isoleucine acceptance by sulfur-deficient transfer RNA from Escherichia coli.

Sulfur-deficient tRNA, isolated from Escherichia coli HfrC, rel-, met-, cys-, lambda, after cysteine starvation, was found to have an increased acceptance of isoleucine in proportion to the deficiency of 4-thiouridine. Isoleucine acceptance was not altered in the presence of other amino acids of CTP, and the higher acceptance was observed over a wide range of magnesium, isoleucine, tRNA and enzyme concentrations. The Vmax value for sulfur-deficient tRNA was more than three times greater than observed for normal tRNA. Methylated albumin kieselguhr (MAK) chromatography revealed three isoacceptor peak for normal tRNA, while sulfur-deficient tRNA was missing tRNAile, and exhibited a larger, shifted peaks for tRNA normal tRNA, while sulfur-deficient tRNA was missing tRNAille 2, and exhibited a large shifted peak for tRNAile 3 . Treatment with crude RNA sulfurtransferase both lowered the isoleucine acceptance for sulfur-deficient tRNA to that seen for normal tRNA, and restored the missing isoacceptor on MAK. The possibility that thionucleotides may play a role in the aminoacylation of tRNAile in E. coli is discussed.

Amino Acyl-tRNA Synthetases↗
PubMed1976

Persistent herpes simplex virus infections established in two Burkitt lymphoma derived cell lines.

Examination of P3HR-I cells (Epstein-Barr virus [EBV] producer) persistently infected with the MAL strain of herpes simplex virus type I (HSV-I) suggested that only a few cells were actively producing a virus indistinguishable from HSV-I (MAL) despite the presence of immunofluorescent HSV-I antigens associated with the majority of cells. EBV-specific immunofluorescence was not altered in HSV-I persistently infected P3HR-I cells. HSV-I persistently infected cells, labelled for 72 h with 14C-thymidine, incorporated approx. 8% of the label into cell associated HSV-I DNA as resolved by caesium chloride gradients. Values greater than 8% of the total were suggested by hybridization of gradient fractions with 3H-HSV-I DNA. To determine whether the establishment of HSV persistent infections in Burkitt lymphoma derived cells was a general phenomenon, six strains of HSV-I (MAL, KOS, Patton, Syn R, BF and SYN V) and two strains of type 2 (333 and MS) were used to infect the P3HR-I and Raji (EBV non-producer) cell lines derived from Burkitt lymphomas. In P3HR-I cells, persistent infections were established with all strains of HSV-I but not with HSV-2. In Raji cells, persistent infections were established with all strains of HSV-I, except Syn V, and with both strains of HSV-2. No external support was required to maintain these infections.

Adsorption↗
PubMed1975

Bacteroides pericardial effusion and cardiac tamponade in a patient with chronic renal failure.

A 31-year-old woman with chronic renal insufficiency and recurrent pericarditis developed an enlarging cardiac silhouette and physical signs of cardiac tamponade. Cardiac catheterization demonstrated pericardial effusion with hemodynamic evidence of cardiac compression. At pericardial exploration, 1.5 L. of foul-smelling purulent material was removed from a distended pericardial sac. Cultures of both the exudate and pericardium revealed pure growth of Bacteroides fragiles. The patient was subsequently treated with intravenous chloramphenicol and has had an uncomplicated clinical course since that time. This represents the first reported case of cardiac tamponade secondary to culturally proved Bacteroides pericarditis in the setting of chronic renal insufficiency.

Adult↗
PubMed1975

A p60 polypeptide in the feline leukemia virus pseudotype of Moloney sarcoma virus with murine leukemia virus p30 antigenic determinants.

A 60,000-dalton polypeptide (p60) has been identified in the feline leukemia virus (FeLV) pseudotype of Moloney sarcoma virus [MSV(FeLV)]. This polypeptide is present in the purified virus complex in concentrations greater than either the murine p30 or the feline p27. Purified p60 crossreacts immunologically with murine p30 group antiserum and contains several interspecies determinants, whereas the group specific determinant of FeLV p27 is not detected. Comparison of peptide fingerprints of p60 and murine p30 show many peptides in common. Limited digestion of p60 with either trypsin or chymotrypsin produced p30-35 and p20 peptides which retain the MuLV p30 group and interspecies antigenic activities. The p30 produced by both enzymes comigrates in polyacrylamide gels with the murine p30 of MSV(FeLV), thus suggesting that p60 may be an uncleaved precursor to p30.

Chromatography, Gel↗
PubMed1975

RNA sulfurtransferase activity in rat liver and chemically induced hepatomas.

RNA sulfurtransferase activity has been detected in rat liver and in hepatomas from rats fed a diet containing 0.06% 3'-methyl-4-dimethylaminoazobenzene for 14 to 18 weeks. The reaction measured was the transfer of sulfur from cysteine to acceptor sites in Escherichia coli B transfer RNA (tRNA). Specific activities of the enzymes in liver and hepatoma supernatant fractions were similar, as were the rates and extents of sulfur transfer to tRNA. DEAE-cellulose chromatography of digests of the [35S]tRNA reaction products revealed 3 peaks associated with nucleotide material, the amounts of these peaks differing in tRNA from liver and hepatoma systems. This may suggest differences in specific sulfurtransferases in these tissues.

Animals↗