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Biomedical subjects

M J Swanson

Publications and source records attributed to M J Swanson.

14 recordsLinked to original sources
PubMed1998

The yeast TAF145 inhibitory domain and TFIIA competitively bind to TATA-binding protein.

The Drosophila 230-kDa TFIID subunit (dTAF230) interacts with the DNA binding domain of TATA box-binding protein (TBP) which exists in the same complex. Here, we characterize the inhibitory domain in the yeast TAF145 (yTAF145), which is homologous to dTAF230. Mutation studies show that the N-terminal inhibitory region (residues 10 to 71) can be divided into two subdomains, I (residues 10 to 37) and II (residues 46 to 71). Mutations in either subdomain significantly impair function. Acidic residues in subdomain II are important for the interaction with TBP. In addition, yTAF145 interaction is impaired by mutating the basic residues on the convex surface of TBP, which are crucial for interaction with TFIIA. Consistently, TFIIA and yTAF145 bind competitively to TBP. A deletion of the inhibitory domain of yTAF145 leads to a temperature-sensitive growth phenotype. Importantly, this phenotype is suppressed by overexpression of the TFIIA subunits, indicating that the yTAF145 inhibitory domain is involved in TFIIA function.

Amino Acid Sequence↗
PubMed1991

The SIR1 gene of Saccharomyces cerevisiae and its role as an extragenic suppressor of several mating-defective mutants.

The SIR1 gene product of Saccharomyces cerevisiae is one of several proteins involved in repressing transcription of the silent mating-type genes. Strains with mutations in the genes coding for these proteins are defective in mating due to derepression of the silent loci. We have found that overexpression of the SIR1 gene suppresses the mating defects of several of these mutants, including nat1 and ard1 mutants (the products of these two genes are responsible for N-terminal acetylation of a subset of yeast proteins), certain sir3 mutants, and a histone H4 mutant. The SIR1 gene has been sequenced and found to contain an open reading frame coding for a 678-amino-acid protein.

Amino Acid Sequence↗
PubMed1987

Successful treatment of right ventricular failure with atrial septostomy.

In the case reported, a patient with severe right ventricular failure following coronary revascularization was successfully weaned from cardiopulmonary bypass following creation of an atrial septal defect. This technique facilitated rapid decompression of the failing right ventricle by shunting blood to the more compliant left ventricle, thus augmenting left ventricular preload and enhancing cardiac output. Recovery of right ventricular function was demonstrated by progressive hemodynamic improvement, as well as reduction of right-to-left intracardiac shunting and resolution of arterial hypoxemia.

Heart Diseases↗
PubMed1987

Baccalaureate nursing education: students' perceptions of roles, effort, and performance.

This study analyzed differences in the perceptions of three groups of nursing students regarding their total role investment, quality of effort, and nursing performance. One hundred ninety-four senior baccalaureate nursing students enrolled in generic or RN completion programs responded to a questionnaire containing three measurements: The Total Role Investment Scale, Pace's College Questionnaire, and Lubno's modified version of Schwirian's Six-Dimension Scale of Nursing Performance. Significant differences were found among the three groups of students in biographical data, total role involvement, quality of effort, and nursing performance. Quality of effort and total role investment were the best predictors of nursing performance. The type of baccalaureate nursing program was not a significant predictor of nursing performance.

Adult↗
PubMed1979

Glucuronidation of lipophilic substrates: preparation of 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid in multimilligram quantities by microsomal UDP-glucuronyl transferase.

A convenient method for the enzymic conversion of multimilligram quantities of 3-hydroxybenzo[a]pyrene to 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid in 90% yield is described. Commercially available freeze-dried rabbit liver microsomes were incubated in the presence of UDPGA, 3-hydroxybenzo[a]pyrene, and Triton X-100 detergent (Figure 1). The course of the biosynthetic reaction was followed by fluorimetry. The glucuronide product was extracted from the acidified incubation supernate with ethyl acetate and the acid function of the glucuronide was utilized in an acid-base extraction procedure to purify the glucuronide from biological and unreacted starting material. The glucuronide precipitated from ethyl acetate and was collected by centrifugation. High pressure liquid chromatography and spectroscopic techniques were used to verify the structure and purity of 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid.

Animals↗
PubMed1978

Preparation, isolation, analysis, and characterization of 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid: a metabolite of 3-hydroxybenzo[a]pyrene with potentially high carcinogenic activity.

The aglycone, 3-hydroxybenzo[a]pyrene, was metabolized to 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid in the presence of uridine 5'-diphosphoglucuronic acid and rabbit liver microsomes. The course of the biosynthetic reaction was followed by fluorimetry and reverse-phase, paired-ion high pressure liquid chromatography (HPLC). Also, the HPLC system was used to analyze for glucuronide and 3-hydroxybenzo[a]pyrene during the isolation procedure. The existence of a glucuronide of 3-hydroxybenzo[a]pyrene was determined by radiotracer and enzymic techniques, utilizing the HPLC system. Field desorption and direct inlet mass spectral techniques were used to characterize the 3-hydroxybenzo[a]pyrene glucuronide.

Animals↗
PubMed1977

A simple multiple chamber apparatus for measuring chemotaxis of polymorphonuclear leukocytes utilizing centrifugation of the chambers before incubation.

A simple apparatus for measuring chemotaxis is described which contains thirty chambers per unit. Only very few cells and small volumes of chemotactic factor solution are required per chamber. For satisfactory results the apparatus must be centrifuged briefly prior to incubation. Under these conditions results can be obtained that are equivalent to or, with short incubation times, superior to other commonly used modified Boyden chambers.

Centrifugation↗
PubMed1976

Measurement of chemotaxis of human polymorphonuclear leukocytes in filters by counting the number of cells in a single plane and comparison with leading front method.

A method is described for measuring the chemotactic response in filters of human neutrophils by counting the number of cells in a single plane at a constant distance below the top of the filters. This method gives results that are similar to those obtained by counting the total number of cells that have migrated into the filters. The results obtained by this method are compared with the leading front method. Under most conditions the results are similar whether obtained by the leading front or cell number methods except that counting the number of cells is often more sensitive. In the presence of p-nitrophenyl 4-chlorobutylphosphonate, however, the chemotactic response appeared to be inhibited as determined by counting the number of cells stimulated to migrate but enhanced as measured by the leading front method.

Blood Cell Count↗