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Biomedical subjects

R J Roberts

Publications and source records attributed to R J Roberts.

At least 325 records · Page 18Linked to original sources
PubMed1975

The 3'-terminal nucleotide sequences of adenovirus types 2 and 5 DNA.

Short nucleotide sequences at the 3'-termini of adenovirus types 2 and 5 DNA have been determined using T4 DNA polymerase as described by P. T. Englund (1972). The terminal sequences of both serotypes appear to be completely identical. Both molecular ends of type 2 as well as of type 5 DNA terminate with the sequence ...pCpC...pGpApTpG3', consistent with the presence of an inverted terminal repetition in adenovirus DNA.

Adenoviridae↗
PubMed1975

Acute iron intoxication with intestinal infarction managed in part by small bowel resection.

This report deals with a case of acute iron intoxication in a child in which acute and chronic gastrointestinal abnormalities developed as a consequence of severe intestinal infarction and corrosion. Microscopic examination of resected small bowel revealed prominent iron deposits in areas of necrosis, in basement membranes of lymphatics, capillaries, and venules, and within platelet-fibrin thrombi. The clinical history and microscopic findings are consistent with the hypothesis of a direct action of absorbed iron on vascular walls as the pathophysiologic mechanism for the toxic effects of iron on the gastrointestinal tract. Acute and long-term management of iron intoxication is discussed in the context of the observations in this case.

Deferoxamine↗
PubMed1975

Influence of carbon monoxide, hypoxic hypoxia or potassium cyanide pretreatment on acute carbon monoxide and hypoxic hypoxia lethality.

Pre-exposure of mice to 500 or 1000 ppm of carbon monoxide (CO) for 4 hours resulted in a significant decrease in lethality induced by exposure to 2500 ppm of CO 24 hours later. Pre-exposure to CO had no effect on lethality induced by hypoxic hypoxia (low inspired O2 tension) or potassium cyanide (KCN). Pre-exposure to 10% O2 for 4 hours significantly decreased lethality induced 24 hours later by CO or 7% O2 exposures lethality induced 24 hours later by CO or 7% O2 exposures but had no effect on KCN-induced lethality. Pretreatment with a nonlethal dose of KCN had no significant effect on lethality induced 24 hours later by exposure to CO (2500 ppm), 7% O2 or KCN. The alterations in CO lethality were not associated with alterations in carboxyhemoglobin levels. Studies of oxygen consumption and indicators of oxygen delivery to tissues (P50 and red blood cell 2,3-diphosphoglycerate) failed to provide any evidence of pretreatment alteration. Examination of blood lactate, pyruvate and lactate/pyruvate ratios in control and pre-exposed mice after a short exposure to 2500 ppm of CO showed significantly lower lactate and lactate/pyruvate ratios in the pre-exposed mice as compared to controls. These data suggest that animals pre-exposed to 1000 ppm of CO and 10% O2 are less hypoxic than non-pre-exposed animals even through their oxygen delivery system is unchanged.

Adenosine Diphosphate↗
PubMed1974

The length of the terminal repetition in adenovirus-2 DNA.

Adenovirus-2 DNA was end-labeled by partial digestion with Escherichia coli exonuclease III and resynthesis with the DNA polymerase from avian myeloblastosis virus and alpha-(32)P-labeled deoxyribonucleoside triphosphates. This end-labeled DNA was cleaved with several specific endonucleases and the terminal fragments were characterized by gel electrophoresis and pyrimidine tract analysis. Two endonucleases gave identical fragments from both ends, presumably from cleavage within the inverted terminal repetition, while all other endonucleases gave dissimilar fragments from the two ends. From the sizes of these fragments it is estimated that the inverted terminal repetition is between 100 and 140 nucleotide pairs long.

Adenoviridae↗