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Biomedical subjects

S M Weissman

Publications and source records attributed to S M Weissman.

At least 235 records · Page 13Linked to original sources

Nucleotide sequence of an RNA from cells infected with adenovirus 2.

The principal nucleotide sequence of an RNA in KB cells infectedwith adenovirus 2 has been determined. As isolated, the molecule shows some terminal and internal heterogeneity. The sequence permits extensive base pairing and contains prominent repeating sequences. A portion of the sequence resembles a sequence found in several transfer RNA's.

Adenoviridae↗

Characteristics of the RNA synthesized in vitro by the normal human small lymphocyte and the changes induced by phytohemagglutinin stimulation.

These studies demonstrate that the circulating human small lymphocyte synthesizes ribonucleic acid (RNA) of high molecular weight which is not primarily a ribosomal precursor and which is, in part, complementary to human deoxyribonucleic acid (DNA). The stimulation of these lymphocytes by PHA brings a cell population in which few ribosomes are synthesized to a functional condition in which a large amount of these particles are produced. This increase in the synthesis of ribosomal RNA is one of the earliest and most relevant effects of PHA on the RNA metabolism of small lymphocytes.

Humans↗

Direct measurement of the rates of synthesis of plasma proteins in control subjects and patients with gastrointestinal protein loss.

The guanido carbon of hepatic arginine is the common precursor of urea and of the arginine of plasma proteins synthesized in the liver. It is possible to measure the momentary synthetic rates of plasma proteins by "pulse labeling" this arginine pool with bicarbonate-(14)C. In the current study, this method has been adapted in order to use urinary urea data and was applied to control subjects and patients with gastrointestinal protein loss. The assumptions required for this determination are discussed. There was close agreement between albumin synthetic rates measured by this method and albumin catabolic rates derived from simultaneous albumin-(131)I studies, supporting the validity of the method and suggesting that there is relatively little fluctuation in the rate of albumin synthesis from time to time. The albumin synthetic rates in six control subjects averaged 5.8 mg/kg per hr, while those of five patients with gastrointestinal protein loss averaged 7.2 mg/kg per hr. Thus in these patients, there was relatively little acceleration of albumin synthesis in response to continued loss of plasma proteins into the gastrointestinal tract. Fibrinogen synthetic rates averaged 1.9 mg/kg per hr in five control subjects and 3.2 mg/kg per hr in five patients with gastrointestinal protein loss. Transferrin synthetic rates exhibited considerable individual variation in both groups and averaged 0.24 mg/kg per hr in four control subjects and 0.31 mg/kg per hr in five patients with gastrointestinal protein loss. The method employed in this study offers several advantages in studying plasma protein metabolism. It provides a direct measurement of protein synthesis, applicable to several proteins simultaneously, does not require a long-term steady state in the metabolism of the proteins, and is capable of measuring short-term fluctuations in synthetic rates. Therefore, this approach is applicable to the investigation of the physiological factors controlling the rates of synthesis for plasma proteins.

Amyotrophic Lateral Sclerosis↗

Nucleotide sequence of KB cell 5S RNA.

The nucleotide sequence of 5S RNA derived from KB carcinoma cell ribosomes has been determined. The molecule has a length of either 120 or 121 nucleotides with uridine at its 3'-terminus and guanylic acid at its 5'-terminus. If, in addition to Watson-Crick base-pairing, one accepts occasional base-pairing of guanylic acid to uridylic acid, long sequences of complementary nucleotides can be identified within the molecule. Two regions of the molecule contain sequences complementary to four or five bases in the pentanucleotide sequence guanylic acid, ribothymidylic acid, pseudouridylic acid, cytidylic acid, guanylic acid, which is common to most transfer RNA molecules. This is the first time the sequence of an animal-cell RNA has been determined.

Autoradiography↗