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D J Hoffman

Publications and source records attributed to D J Hoffman.

117 records · Page 7Linked to original sources
PubMed1973

RNA initiation with dinucleoside monophosphates during transcription of bacteriophage T4 DNA with RNA polymerase of Escherichia coli.

The effects of dinucleoside monophosphates on the transcription of phage T4 DNA by E. coli RNA polymerase have been examined at various concentrations of the sigma subunit and extremely low concentration of ribonucleoside triphosphate. The following conclusions were reached: (i) Labeled specific dinucleoside monophosphates are incorporated as chain initiators. (ii) When the ratio of sigma factor to core enzyme is small, there is a general stimulation by most 5'-guanosyl dinucleoside monophosphates. (iii) When the ratio is increased or holoenzyme is present, ApU, CpA, UpA, and GpU are the most effective stimulators. (iv) At high concentrations of sigma factor, only certain adenosine-containing dinucleoside monophosphates (ApU, CpA, UpA, and ApA) stimulate the reaction. (v) Competition hybridization studies indicate that the RNAs stimulated by dinucleoside monophosphates (ApU, CpA, UpA, and GpU) are of the T4 "early" type. (vi) Studies involving both combinations of stimulatory dinucleoside monophosphates and competitive effects of these compounds on chain initiation by ATP and GTP suggest that the stimulatory dinucleoside monophosphates act as chain initiators and may recognize part of a continuous sequence in a promoter region. Studies based on the incorporation of (3)H-labeled stimulatory dinucleoside monophosphates support the above conclusions.

Adenine Nucleotides↗
PubMedDate not supplied

Pulmonary function and electrolyte balance following spironolactone treatment in preterm infants with chronic lung disease: a double-blind, placebo-controlled, randomized trial.

OBJECTIVE: To study the effect of spironolactone on dietary electrolyte supplementation, pulmonary function, and electrolyte balance in premature infants with chronic lung disease. STUDY DESIGN: A double-blind, randomized, and placebo-controlled trial was designed to study two groups of low birth weight infants with chronic lung disease at Pennsylvania Hospital. The placebo group received chlorothiazide and a placebo, and the spironolactone group received chlorothiazide and spironolactone during the 2-week study period. A two-tailed t-test was used to determine equivalence between the two groups. RESULTS: Pulmonary compliance, resistance and tidal volume, serum sodium and potassium, and FIO2, were not statistically different between the two groups. The need for sodium and/or potassium chloride did not differ between the two groups, nor did the quantity of each salt. CONCLUSION: The addition of spironolactone did not reduce the requirement for supplemental electrolytes, nor did it improve pulmonary mechanics or electrolyte balance.

Chronic Disease↗